Measurement system, substrate processing system, and device manufacturing method

ABSTRACT

A measurement system to be used in a manufacturing line for micro-devices is provided independently from an exposure apparatus. The measurement system has measurement devices that each performs measurement processing on substrates (e.g., substrates that have gone through at least one processing but before being coated with a sensitive agent), and a carrying system for performing delivery of substrates to/from the measurement devices. The measurement devices include a first measurement device that acquires position information on a plurality of marks formed on a substrate under a setting of a first condition, and a second measurement device that acquires position information on a plurality of marks formed on another substrate (e.g., another substrate included in the same lot as the substrate on which acquiring position information is performed under the setting of the first condition in the first measurement device) under a setting of a first condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation U.S. patent application Ser. No.16/363,057 filed Mar. 25, 2019, which is a continuation of InternationalApplication PCT/JP2017/033954, with an international filing date of Sep.20, 2017, claiming priority to Japanese Application No. 2016-192810filed Sep. 30, 2016, the disclosures of these applications being herebyincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a measurement system, a substrateprocessing system, and a device manufacturing method, and moreparticularly to a measurement system used in a micro-devicemanufacturing line, a substrate processing system that includes themeasurement system, and a device manufacturing method that uses anexposure apparatus structuring a part of the substrate processingsystem.

Description of the Background Art

In a lithography process, when overlay exposure is performed on thewafer, in the wafer that has gone through processing processes such asresist coating, developing, etching, CVD (Chemical Vapor Deposition),and CMP (Chemical Mechanical Polishing), distortion may occur due to theprocesses in the arrangement of the shot areas on the previous layer,and the distortion may cause a decrease in the overlay accuracy. Takingsuch a point into consideration, recent exposure apparatuses have a gridcorrection function and the like for correcting not only a primarycomponent of wafer deformation, but also a nonlinear component and thelike of the shot arrangement that occurs due to the processes (forexample, refer to U.S. Patent Application Publication No. 2002/0042664).

However, requirements on overlay accuracy is becoming more and moresevere due to finer integrated circuits, therefore, to performcorrection with higher accuracy, it is essential to increase the numberof sample shot areas in wafer alignment (EGA), that is, to increase thenumber of marks that should be detected. Therefore, in recent years, atwin-stage type exposure apparatus came to be employed which allows anincrease in the number of sample shot areas while maintainingthroughput.

SUMMARY OF THE INVENTION

According to a first aspect, there is provided a measurement system usedin a manufacturing line for micro-devices, comprising: a plurality ofmeasurement devices in which each device performs measurement processingon a substrate; and a carrying system to perform delivery of a substratewith the plurality of measurement devices, wherein the plurality ofmeasurement devices includes a first measurement device that acquiresposition information on a plurality of marks formed on a substrate, anda second measurement device that acquires position information on aplurality of marks formed on a substrate, and position information on aplurality of marks formed on a substrate can be acquired under a settingof a first condition in the first measurement device, and positioninformation on a plurality of marks formed on another substrate can beacquired under a setting of the first condition in the secondmeasurement device.

According to a second aspect, there is provided a measurement systemused in a manufacturing line for micro-devices, comprising: a pluralityof measurement devices in which each device performs measurementprocessing on a substrate; and a carrying system to perform delivery ofa substrate with the plurality of measurement devices, wherein theplurality of measurement devices includes a first measurement devicethat acquires position information on a plurality of marks formed on asubstrate, and a second measurement device that acquires positioninformation on a plurality of marks formed on a substrate, and positioninformation on a plurality of marks formed on a substrate can beacquired in the first measurement device, and position information on aplurality of marks formed on another substrate included in the same lotas the substrate can be acquired in the second measurement device.

According to a third aspect, there is provided a measurement system usedin a manufacturing line for micro-devices, comprising: a plurality ofmeasurement devices in which each device performs measurement processingon a substrate; and a carrying system to perform delivery of a substratewith the plurality of measurement devices, wherein the plurality ofmeasurement devices includes a first measurement device that acquiresposition information on a plurality of marks formed on a substrate, anda second measurement device that acquires position information on aplurality of marks formed on a substrate, and position information on aplurality of marks formed on a substrate can be acquired under a settingof a first predetermined condition in the first measurement device, andposition information on a plurality of marks formed on another substratecan be acquired under a setting of a second predetermined conditiondifferent from the first predetermined condition in the secondmeasurement device.

According to a fourth aspect, there is provided a measurement systemused in a manufacturing line for micro-devices, comprising: a firstmeasurement device that performs measurement processing on a substrate;and a second measurement device that performs measurement processing ona substrate, wherein measurement processing with the first measurementdevice and measurement processing with the second measurement device canbe concurrently executed.

According to a fifth aspect, there is provided a measurement system usedin a manufacturing line for micro-devices, comprising: a firstmeasurement device that performs measurement processing on a substrate;and a second measurement device that performs measurement processing ona substrate, wherein a substrate that has been measured and processed byone of the first measurement device and the second measurement devicecan be measured and processed by the other of the first measurementdevice and the second measurement device.

According to a sixth aspect, there is provided a substrate processingsystem, comprising: the measurement system according to any one of thefirst aspect to the fifth aspect; and an exposure apparatus that has asubstrate stage on which the substrate that has completed measurement ofposition information of the plurality of marks by at least one of thefirst measurement device and the second measurement device of themeasurement system is mounted, and to the substrate mounted on thesubstrate stage, performs alignment measurement in which positioninformation of a part of marks selected from a plurality of marks on thesubstrate is acquired and exposure in which the substrate is exposedwith an energy beam.

According to a seventh aspect, there is provided a substrate processingsystem, comprising: a first measurement system and a second measurementsystem structured from the measurement system according to any one ofthe first aspect to the fifth aspect; and an exposure apparatus that hasa substrate stage on which the substrate that has completed measurementof position information on the plurality of marks by at least one of thefirst measurement device and the second measurement device of themeasurement system is mounted, and to the substrate mounted on thesubstrate stage, performs alignment measurement in which positioninformation on apart of marks selected from a plurality of marks on thesubstrate is acquired and exposure in which the substrate is exposedwith an energy beam, wherein acquiring position information on theplurality of marks performed in at least one of the first measurementdevice and the second measurement device that the first measurementsystem is equipped with is performed on a substrate that has gonethrough at least one processing of; cleaning, oxidation/diffusion, filmdeposition, etching, ion implantation, and CMP and is before coating ofa sensitive agent for the next exposure, acquiring position informationon the plurality of marks performed in at least one of the firstmeasurement device and the second measurement device that the secondmeasurement system is equipped with is performed on a substrate beforeetching processing, the substrate having been exposed by the exposureapparatus and has been developed, and acquiring position information onthe plurality of marks for different substrates by each of the firstmeasurement system and the second measurement system is performedconcurrently with alignment measurement and exposure to differentsubstrates by the exposure apparatus.

According to an eighth aspect, there is provided a device manufacturingmethod, comprising: exposing a substrate using an exposure apparatusthat structures a part of the substrate processing system according toone of the sixth aspect and the seventh aspect, and developing thesubstrate that has been exposed.

BRIEF DESCRIPTION OF DRAWINGS

In the accompanying drawings;

FIG. 1 is a block diagram showing a substrate processing systemaccording to an embodiment, along with other apparatuses to be used in amicro-device manufacturing line;

FIG. 2 is a perspective view of an external appearance showing ameasurement system that the substrate processing system in FIG. 1 isequipped with;

FIG. 3 is a planar view showing the measurement system in FIG. 1 withthe ceiling section of a chamber removed;

FIG. 4 is a perspective view schematically showing a structure of ameasurement device that structures a part of the measurement system;

FIG. 5A is a partly omitted front view (a view when viewed from the −Ydirection) of the measurement device in FIG. 4, and FIG. 5B is a partlyomitted cross-sectional view of the measurement device when across-section is taken in the XZ plane that passes through an opticalaxis AX1 of a mark detection system;

FIG. 6 is a partly omitted cross-sectional view of the measurementdevice when a cross-section is taken in the YZ plane that passes throughoptical axis AX1 of the mark detection system;

FIG. 7 is a view used to explain a structure of a second positionmeasurement system;

FIG. 8 is a block diagram showing an input output relation of acontroller which mainly structures a control system of the measurementdevice;

FIG. 9 is a view schematically showing an exposure apparatus shown inFIG. 1;

FIG. 10 is a block diagram showing an input output relation of anexposure controller that the exposure apparatus is equipped with;

FIG. 11 is a flowchart corresponding to a processing algorithm of acontroller 60 _(i), when processing wafers in one lot;

FIG. 12 is a view schematically showing a processing flow of ameasurement method of position information (coordinate positioninformation) of an X mark and a Y mark performed in the substrateprocessing system in FIG. 1;

FIG. 13 is a view (No. 1) schematically showing a processing flow of anoverlay displacement measurement method performed in the substrateprocessing system in FIG. 1;

FIG. 14 is a view (No. 2) schematically showing a processing flow of anoverlay displacement measurement method performed in the substrateprocessing system in FIG. 1; and

FIG. 15 is a view showing an example of a manufacturing process of asemiconductor device.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment will be described, based on FIGS. 1 to 14.FIG. 1 is a block diagram, showing a substrate processing system 1000according to a first embodiment used in a manufacturing line formanufacturing micro-devices (e.g., semiconductor devices), along withother devices used in the manufacturing line.

Substrate processing system 1000, as is shown in FIG. 1, is equippedwith an exposure apparatus 200 and a coater/developer 300 (resistcoating/developing apparatus) that are connected in-line with eachother. Also, substrate processing system 1000 is equipped with ameasurement system 500 ₁ and a measurement system 500 ₂. Hereinafter,coater/developer 300 will be expressed shortly referred to as C/D 300.Note that connected in-line means that different apparatuses areconnected so that a carrying route of a wafer (substrate) issubstantially connected, and in the description, terms such as“connected in-line” and “in-line connection” will be used in such ameaning. For example, in the case two different apparatuses areconnected in-line, a wafer (substrate) that has finished processing inone apparatus can be sequentially carried to the other apparatus using acarrier mechanism such as a robot arm. Note that the case in which thedifferent apparatuses are connected via an interface section may also becalled an “in-line connection.”

Measurement system 500 ₁, here, is equipped with three measurementdevices 100 ₁ to 100 ₃ arranged adjacent to one another in apredetermined direction inside one chamber 502 (refer to FIGS. 2 and 3),a measurement system controller 530 ₁ which generally controls theentire measurement system 500 ₁, and the like. Each of the measurementdevices 100 ₁ to 100 ₃ has a controller 60 _(i) (i=1 to 3), and each ofthe controllers 60 _(i) is connected to measurement system controller530 ₁. Note that each of the measurement devices 100 ₁ to 100 ₃ may becontrolled by measurement system controller 530 ₁, without beingequipped with controller 60 _(i) (i=1 to 3).

Measurement system 500 ₂ is equipped with three measurement devices 100₄, 100 ₅, and 100 ₆, arranged adjacent to one another in a predetermineddirection inside one chamber (not shown), and a measurement systemcontroller 530 ₂ which generally controls the entire measurement system500 ₂, and the like. Measurement devices 100 ₄, 100 ₅, and 100 ₆ havecontrollers 60 ₄, 60 ₅, and 60 ₆, respectively, and each of thecontrollers 60 _(i) (i=4 to 6) is connected to measurement controller530 ₂. Note that each of the measurement devices 100 ₄ to 100 ₆ may becontrolled by measurement system controller 530 ₂, without beingequipped with controller 60 _(i) (i=4 to 6).

Exposure apparatus 200 and C/D 300 that substrate processing system 1000is equipped with both have a chamber, and the chambers are disposedadjacent to each other.

An exposure controller 220 that exposure apparatus 200 has, acoater/developer controller 320 that C/D 300 has, measurement systemcontroller 530 ₄, and measurement system controller 530 ₂ are connectedto one another, via a local area network (LAN) 1500. To LAN 1500, a hostcomputer (HOST) 2000 that controls the entire manufacturing line, ananalysis device 3000, and a group of devices performing various types ofprocessing (processing of a pre-process in a wafer process) under thecontrol of host computer 2000 are also connected. Of the group ofdevices, FIG. 1 representatively shows an etching device 2100, a CMPdevice 2200, and a film deposition device 2300 such as a CVD device.Other than these apparatuses, a cleaning device, an oxidation/diffusiondevice, an ion implantation device and the like are connected to LAN1500.

Note that substrate processing system 1000 may include at least one ofhost computer 2000, analysis device 3000, etching device 2100, CMPdevice 2200, and film deposition device 2300.

First of all, the measurement systems will be described. Here, whilemeasurement system 500 ₁ and measurement system 500 ₂ have a differenceof the substrate subject to measurement being a substrate beforeexposure or after exposure, the structure is similar to each other withthe systems having a similar function; therefore, measurement system 500₁ will be representatively discussed and described in the descriptionbelow. FIG. 2 shows a perspective view of an external appearance ofmeasurement system 500 ₁. Measurement system 500 ₁ is installed on afloor F of a clean room apart from other devices that structuresubstrate processing system 1000. That is, measurement system 500 ₁ isnot connected in-line with exposure apparatus 200 and C/D 300.

Measurement system 500 ₁ is equipped with; chamber 502 in which thethree measurement devices 100 ₁ to 100 ₃ are arranged, and a carriersystem 510 arranged at one side of chamber 502. In the embodiment,carrier system 510 is an EFEM (Equipment Front End Module) system.Hereinafter, carrier system 510 is also called EFEM system 510.

Note that as it will be described later on, while carrier system 510 ofthe embodiment is for FOUP (Front-Opening Unified Pod), the carrier isnot limited to FOUP, and other types of carriers (e.g., SMIF pod) thatcan house one or a plurality of wafers may be handled in carrier system510.

In the description below, a direction in which chamber 502 and EFEMsystem 510 are arranged will be described as an X-axis direction, adirection perpendicular to the X-axis within a plane parallel to floorsurface F will be described as a Y-axis direction, and a directionorthogonal to the X-axis and the Y-axis will be described as a Z-axisdirection.

As is shown in FIG. 2, chamber 502 has a rectangular parallelepipedshape, and in a first space therein, as is shown in FIG. 3, measurementdevices 100 ₁ to 100 ₃ are housed arranged in the X-axis direction. FIG.3 shows a planar view of measurement system 500 ₁ with the ceilingsection of chamber 502 removed, and in FIG. 3, a chamber 101 _(i) (i=1to 3) that each of measurement devices 100 ₁ to 100 ₃ has is shown. Notethat each of measurement devices 100 ₁ to 100 ₃ does not have to beequipped with chamber 101 _(i).

Since the plurality of measurement devices 100 ₁ to 100 ₃ are arrangedin the X-axis direction, measurement system 500 ₁ can be equipped withthe plurality of measurement devices 100 ₁ to 100 ₃ without increasingthe width in the Y-axis direction of measurement system 500 ₁. In afactory where measurement system. 500 ₁ and the like is installed, apathway for operators extends in the Y-axis direction, and devices thatperform various types of processing described above (such as etchingdevice 2100 and CMP device 2200) are arranged along the pathway.Consequently, to effectively use floor surface F of the factory, it isimportant to suppress the width in the Y-axis direction of measurementsystem 500 ₁.

Also, on the −Y side of the first space in chamber 502, a carryingsystem 521 is arranged that can deliver/receive a wafer to/from each ofmeasurement devices 100 ₁ to 100 ₃. Note that in the description below,for the sake of convenience, space on the −Y side of the first spacewhere carrying system 521 is installed is to be called a second space.In FIG. 2, the bold broken line shows a virtual partition between thefirst space and the second space.

Adjacent to chamber 502 on the −X side (front surface side), EFEM system510 is installed on floor surface F. EFEM system 510 is a moduleequipment equipped with an EFEM main body 512 in which a robot forcarrying wafers is installed inside, and a loading port attached to the−X side (front surface side) of EFEM main body 512. To EFEM main body512 at the front surface side, a plurality of loading ports 514 (mayalso be called a carrier mounting device) for FOUP is provided arrangedin the Y-axis direction. Note that in the embodiment, while EFEM mainbody 512 has three loading ports 514, the number of loading ports is notlimited to three, and may be one, two, four, or more than four. Here,FOUP is a carrier that is aimed to carry and store a wafer used in asemiconductor factory of a mini-environment method specified in SEMIstandard E47.1, and is a front opening type cassette integratedcarriage/storage box. In FIGS. 2 and 3, a FOUP 520 is installed on eachof the three loading ports 514, and in the FOUP, at least one wafer ishoused as a measurement target.

In the embodiment, although it is omitted in the drawings, a track railfor OHT (Overhead Hoist Transport) is provided near the ceiling of theclean room directly above the three loading ports 514. OHT is anunmanned carrier that travels in a space of a ceiling level, and by thisOHT, FOUP 520 is delivered to loading port 514.

Each of the three loading ports 514 has a mounting section 515 and anopen/close mechanism 518 (refer to FIG. 3) that opens/closes the coverof FOUP 520 mounted on mounting section 515. Open/close mechanism 518 isprovided in the front part of EFEM main body 512 that faces FOUP 520mounted on mounting section 515 of loading port 514, and can open/closethe cover of FOUP 50 while maintaining the air-tight state inside FOUP520 with respect to the outside. Since this type of open/close mechanismis known, description on the structure and the like of open/closemechanism 518 will be omitted.

Inside EFEM main body 512, a wafer carrier robot 516 (refer to FIG. 3)is provided that can have access to the inside of the three FOUPs in astate where the cover is open to put in and take out the wafer. Notethat to the upper part of EFEM main body 512, a FFU (Fan Filter Unit,not shown) may be provided to keep the degree of cleanliness inside EFEMmain body 512, and temperature controlled air from an air conditionermay be sent to the inside of EFEM main body 512, via FFU. Note that abuffer for stabilizing the temperature of the wafer using thetemperature controlled air from the air conditioner may be providedwithin EFEM main body 512.

At a part on the back surface side of EFEM main body 512 facing thesecond space of chamber 502, an opening is formed, and the opening isopened/closed by an open/close member.

Each part (such as robot 516 and open/close mechanism 518) structuringEFEM system 510 is controlled by measurement system controller 530 ₁(refer to FIG. 1).

Inside the second space of chamber 502, as is shown in FIG. 3, carryingsystem 521 is installed. Provided in the carrying system are; guides522A and 522B that cover almost the whole length of chamber 502extending in the X-axis direction on each of one side and the other sidein the Y-axis direction within the second space, a carrying member 524used for loading that can move back and forth along guide 522A, and acarrying member 526 used for unloading that can move back and forthalong guide 522B.

Carrying member 524 for loading can be moved along guide 522A by alinear motor (will be written as linear motor 522A using the samereference code as the guide in which the stator is incorporated) thathas a stator incorporated in guide 522A and a mover provided in carryingmember 524. Also, carrying member 526 for unloading can be moved alongguide 522B by a linear motor (will be written as linear motor 522B usingthe same reference code as the guide in which the stator isincorporated) that has a stator incorporated in guide 522B and a moverprovided in carrying member 526. Linear motors 522A and 522B arecontrolled by measurement system controller 530 ₁. Note that carryingmembers 524 and 526 may be made to move in a non-contact manner using anair slider or the like. Also, the drive mechanism to move carryingmembers 524 and 526 is not limited to the linear motors (522A and 522B)described above, and may be a structure using a rotation motor and aball screw mechanism.

Guide 522A is arranged at a position higher than that of guide 522B.Therefore, carrying member 524 for loading moves in the space abovecarrying member 526 for unloading.

Note that in carrying system 521 described above, carrying member 524and guide 522A may be used for loading/unloading a wafer, and carryingmember 526 and guide 522B may be used for loading/unloading a wafer.

Also, while carrying system 521 described above can deliver/receive awafer to/from each of the plurality of measurement devices 100 ₁ to 100₃, carrying system 521 may have a carrying device (including the guideand the carrying member) that delivers/receives a wafer only to/frommeasurement device 100 ₁, a carrying device (including the guide and thecarrying member) that delivers/receives a wafer only to/from measurementdevice 100 ₂, and a carrying device (including the guide and thecarrying member) that delivers/receives a wafer only to/from measurementdevice 100 ₃. In this case, each of the carrying devices may have aguide for loading and a carrying member, and a guide for unloading and acarrying member, or a guide used for both loading and unloading and acarrying member.

As is shown in FIG. 3, in measurement device 100 _(i) (i=1 to 3), awafer carrying system 70 _(i) (i=1 to 3) is provided that has amulti-joint type robot which performs delivery/receiving of a waferto/from carrying member 524 and carrying member 526. Wafer carryingsystem 70 _(i) (i=1 to 3) performs delivery/receiving of a wafer to/fromcarrying member 524 and carrying member 526 via an opening of chamber101 _(i).

Carrying member 524 receives a wafer subject to measurement processinginside FOUP 520 from robot 516 at a wafer delivery position (loadingside wafer delivery position) set near the dividing line between mainbody 512 and chamber 502, and carries the wafer to the wafer deliveryposition between wafer carrying system 70 _(i) (i=one of 1 to 3) andmeasurement device 100 _(i). The wafer subject to measurement processingdescribed above of measurement device 100 _(i) (i=1 to 3) in theembodiment is a wafer on which at least exposure of a first layer hasbeen completed and a wafer on which necessary treatment of thepre-process processing in the wafer process such as etching,oxidation/diffusion, ion implantation, and flattening (CMP) has beenapplied after completing development, and is a wafer prior to carriageinto C/D 300 for resist coating.

Note that in the case measurement is performed with at least two ofmeasurement devices 100 ₁ to 100 ₃, carrying member 524 for loadingreceives the wafer subject to measurement on which measurement byanother measurement device 100 _(i) (i=one of 1 to 3) has been completedfrom wafer carrying system 70 _(i) (i=one of 1 to 3), and carries thewafer to the wafer delivery position between wafer carrying system 70_(j) (j=one of 1 to 3, j≠1) and measurement device 100 _(j).

Carrying member 526 receives the wafer on which measurement has beencompleted from wafer carrying system 70 _(i) (i=one of 1 to 3), andcarries the wafer to an unloading side wafer delivery position (aposition below the loading side wafer delivery position describedearlier) set near the dividing line between EFEM main body 512 andchamber 502.

Robot 516 carries (returns) the wafer that has undergone measurementprocessing carried to the unloading side wafer delivery position bycarrying member 526 into FOUP 520.

Referring back to FIG. 1, as each of measurement devices 100 ₁ to 100 ₃,in the embodiment, a measurement device of a similar structure is used.

Note that in the embodiment, while an example was shown of a case inwhich by carrying system 521 that performs delivery of the wafer betweenmeasurement device 100 _(i) such as carrying member 524 and carryingmember 526 being arranged in the second space of chamber 502, the spacein which the wafer is carried by carrying member 524 and carrying member526 is consequently an air-tight space, the embodiment is not limited tothis, and the three measurement devices 100 ₁ to 100 ₃ may be arrangedon floor surface F, and along with these measurement devices 100 ₁ to100 ₃ (whether housed in the same chamber or not), another chamber maybe provided in which an air-tight chamber where carrying system 521 ishoused inside is formed. That is, measurement system 500 ₁ does not haveto be equipped with chamber 502.

Also, instead of carrying members 524 and 526, a multi-joint type robotthat can move back and forth along a guide may be used. In this case,wafer carrying system 70 _(i) does not have to be equipped with themulti-joint type robot, and only has to be equipped with a wafer holdingsection for loading and a wafer holding section for unloading wheredelivery of the wafer is performed with the multi-joint type robot ofcarrying system 521.

Also, in the case the multi-joint type robot is used instead of carryingmembers 524 and 526, EFEM system 510 does not have to be equipped withrobot 516. In this case, the multi-joint type robot of carrying system521 may take out the wafer from FOUP 520, or return the wafer to FOUP520.

Here, measurement device 100 _(i) will be described in detail. FIG. 4schematically shows a perspective view of a structure of measurementdevice 100 _(i). Note that while measurement device 100 _(i) shown inFIG. 4 is actually structured by chamber 101 _(i) described earlier andthe structure part housed inside chamber 101 _(i), in the descriptionbelow, the description related to chamber 101 _(i) will be omitted. Inmeasurement device 100 _(i) according to the embodiment, a markdetection system MDS is provided as is will be described later on, andin the description below, a direction in an optical axis AX1 of markdetection system MDS is to coincide with the Z-axis direction describedearlier, a direction in which a movable stage to be described later onmoves in long strokes within an XY plane orthogonal to the Z-axisdirection is to coincide with the Y-axis direction described earlier,and rotation (tilt) directions around the X-axis, the Y-axis, and theZ-axis will be described as θx, θy, and θz directions, respectively.Here, mark detection system MDS has a cylindrical barrel section 41provided at its lower end (tip), and inside barrel section 41, anoptical system (dioptric system) is housed, consisting of a plurality oflens elements having a common optical axis AX1 in the Z-axis direction.In the description, for the sake of convenience, optical axis AX1 of thedioptric system inside barrel section 41 is to be referred to as opticalaxis AX1 of mark detection system MDS.

FIG. 5A shows a partly omitted front view (a view when viewed from the−Y direction) of measurement device 100 _(i) in FIG. 4, and FIG. 5Bshows a partly omitted cross-sectional view of measurement device 100_(i) when a cross-section is taken in the XZ plane that passes throughoptical axis AX1. Also, FIG. 6 shows a partly omitted cross-sectionalview of measurement device 100 _(i) when a cross-section is taken in theYZ plane that passes through optical axis AX1.

Measurement device 100 _(i), as is shown in FIG. 4, is equipped with; asurface plate 12 having an upper surface almost parallel to the XY planeorthogonal to optical axis AX1, a wafer slider (hereinafter shortlyreferred to as a slider) 10 arranged on surface plate 12 that is movablein predetermined strokes in the X-axis and the Y-axis directions withrespect to surface plate 12 while holding a wafer W and can also movefinely (fine displacement) in the Z-axis, the θx, the θy and the θzdirections, a drive system 20 (refer to FIG. 8) that drives slider 10, afirst position measurement system 30 (not shown in FIG. 4, refer toFIGS. 6 and 8) that measures position information on slider 10 withrespect to surface plate 12 in each of the X-axis, the Y-axis, theZ-axis, the θx, the θy and the θz directions (hereinafter referred to asdirections of six degrees of freedom), a measurement unit 40 that hasmark detection system MDS for detecting a mark on wafer W mounted on(held by) slider 10, a second position measurement system 50 (refer toFIG. 8) that measures relative position information between markdetection system MDS (measurement unit 40) and surface plate 12, and acontroller 60 _(i) (not shown in FIG. 4, refer to FIG. 8) that acquiresmeasurement information according to the first position measurementsystem 30 and measurement information according to the second positionmeasurement system 50 and obtains position information on a plurality ofmarks on wafer W held by slider 10 using mark detection system MDS,while controlling drive of slider 10 by drive system 20.

Surface plate 12 consists of a rectangular parallelepiped member havinga rectangular shape in a planar view, and its upper surface is finishedso that the degree of flatness is extremely high to form a guide surfaceon movement of slider 10. As the material for surface plate 12, amaterial of low thermal expansion coefficient also called a zero thermalexpansion material is used, such as, e.g. an invar alloy, an ultra-lowexpansion steel, or an ultra-low expansion glass ceramics.

In surface plate 12, a total of three cutout shaped spaces 12 a whosebottom section is open is formed, one in the center in the X-axisdirection of a surface on the −Y side, and one each on both ends in theX-axis direction of a surface on the +Y side. Of the three spaces 12 a,FIG. 4 shows space 12 a formed on the surface on the −Y side. Insideeach of the spaces 12 a, a vibration isolator 14 is arranged. Surfaceplate 12 is supported at three points so that its upper surface isalmost parallel to the XY plane, by three vibration isolators 14 on anupper surface parallel to an XY plane of a base frame 16 having arectangular shape in a planar view installed on floor surface F. Notethat the number of vibration isolators 14 is not limited to three.

Slider 10, as is shown in FIG. 6, has one each, or a total of four airhydrostatic bearings (air bearings) 18 attached to the four corners ofthe bottom surface in a state where each of the bearing surfaces isalmost flush with the lower surface of slider 10, and by static pressure(pressure within gap) between a bearing surface of pressurized air whichblows out toward surface plate 12 from these four air bearings 18 andthe upper surface (guide surface) of surface plate 12, slider 10 issupported by levitation via a predetermined clearance (air-gap, gap),such as a clearance of around several μm, on the upper surface ofsurface plate 12. In the embodiment, as the material for slider 10, azero thermal expansion glass (e.g., Zerodur of Schott AG) is used, whichis a kind of zero thermal expansion material.

In the upper part of slider 10, a recess section 10 a is formed, havinga predetermined depth with a circular shape in a planar view whose innerdiameter is slightly larger than the diameter of wafer W, and insiderecess section 10 a, a wafer holder WH whose diameter is almost the sameas that of wafer W is arranged. As wafer holder WH, while a vacuumchuck, an electrostatic chuck, or a mechanical chuck may be used, as anexample, a vacuum chuck of a pin chuck method is to be used. Wafer W isheld by suction by wafer holder WH, in a state where its upper surfaceis almost flush with the upper surface of slider 10. In wafer holder WH,a plurality of suction ports is formed, and the plurality of suctionports is connected to a vacuum pump 11 (refer to FIG. 8) via a vacuumpiping system (not shown). And, operation such as on/off of vacuum pump11 is controlled by controller 60 _(i). Note that one of, or both slider10 and wafer holder WH may be called “a first substrate holding member.”

Also, in slider 10, a vertical movement member (not shown) is providedthat moves vertically, for example, via three circular openings formedin wafer holder WH, and loads the wafer onto wafer holder WH as well asunloads the wafer from wafer holder WH together with wafer carryingsystem 70 _(i) (not shown in FIG. 4, refer to FIG. 8). A driver 13 thatmoves the vertical movement member is controlled by controller 60 _(i)(refer to FIG. 8).

In the embodiment, as wafer holder WH, as an example, a wafer holderthat can hold by suction a 300 mm wafer having a diameter of 300 mm isto be used. Note that in the case wafer carrying system 70 _(i) has anon-contact holding member that holds the wafer on wafer holder WH bysuction in a non-contact manner from above, such as a Bernoulli chuck orthe like, the vertical movement member does not have to be provided inslider 10, and therefore, the circular opening for the vertical movementmember also does not have to be formed in wafer holder WH.

As is shown in FIGS. 5B and 6, on the lower surface of slider 10 in anarea slightly larger than wafer W, a two-dimensional grating(hereinafter simply referred to as a grating) RG1 is arrangedhorizontally (parallel to the surface of wafer W). Grating RG1 includesa reflective diffraction grating whose periodic direction is in theX-axis direction (X diffraction grating) and a reflective diffractiongrating whose periodic direction is in the Y-axis direction (Ydiffraction grating). The pitch between the grid lines of the Xdiffraction grating and the Y diffraction grating is set, for example,to 1 μm.

Vibration isolator 14 is an active type vibration isolation system(so-called AVIS (Active Vibration Isolation System)), and is equippedwith an accelerometer, a displacement sensor (e.g., a capacitivesensor), an actuator (e.g., a voice coil motor), and an air mount whichfunctions as an air damper and the like. Vibration isolator 14 canattenuate vibration of relatively high frequency with the air mount (airdamper) and can also isolate vibration (control vibration) with theactuator. Accordingly, vibration isolator 14 can prevent vibrationtraveling through surface plate 12 and base frame 16. Note that ahydraulic power damper may be used, instead of the air mount (airdamper).

Here, the reason why the actuator is provided in addition to the airmount is because since the internal pressure of the gas within the gaschamber of the air mount is high, control response can be secured onlyto around 20 Hz, therefore, when control of high response is necessary,the actuator has to be controlled according to the output of theaccelerometer not shown. However, fine vibration such as floor vibrationis isolated by the air mount.

The upper end surface of vibration isolator 14 is connected to surfaceplate 12. Air (e.g., compressed air) can be supplied to the air mountvia a gas supply port not shown, and the air mount expands/contracts inpredetermined strokes (e.g., around 1 mm) in the Z-axis directionaccording to the amount of gas (pressure change of the compressed air)filled inside the air mount. Therefore, by vertically movingindividually from below the three places of surface plate 12 using theair mounts that each of the three vibration isolators 14 have, positionof surface plate 12 and slider 10 supported by levitation on the surfaceplate in the Z-axis direction, the θx direction, and the θy directioncan be adjusted arbitrarily. Also, the actuator of vibration isolator 14not only moves surface plate 12 in the Z-axis direction, but also canmove the surface plate in the X-axis direction and the Y-axis direction.Note that movement quantity in the X-axis direction and the Y-axisdirection is smaller than the movement quantity in the Z-axis direction.The three vibration isolators 14 are connected to controller 60 _(i)(refer to FIG. 8). Note that each of the three vibration isolators 14may be equipped with an actuator that can move surface plate 12 not onlyin the X-axis direction, the Y-axis direction, and the Z-axis direction,but also in, for example, directions of six degrees of freedom.Controller 60 _(i) controls the actuators of the three vibrationisolators 14 real time at all times, so that position in directions ofsix degrees of freedom of surface plate 12 to which a head section 32 ofthe first position measurement system 30 to be described later on isfixed maintains a desired positional relation with respect to markdetection system MDS, based on relative position information betweenmark detection system MDS (measurement unit 40) and surface plate 12measured by the second position measurement system 50. Note thatfeedforward control can be performed on each of the three vibrationisolators 14. For example, controller 60 _(i) may perform feedforwardcontrol on each of the three vibration isolators 14, based onmeasurement information on the first position measurement system 30.Note that control of vibration isolator 14 by controller 60 _(i) is tobe described further later on.

Drive system 20, as is shown in FIG. 8, includes a first driver 20A thatmoves slider 10 in the X-axis direction and a second driver 20B thatmoves slider 10 in the Y-axis direction integrally with the first driver20A.

As it can be seen from FIGS. 4 and 6, on a side surface at the −Y sideof slider 10, a pair of movers 22 a each consisting of a magnet unit (ora coil unit) having an inverted L-shape in a side view is fixed at apredetermined spacing in the X-axis direction. On a side surface at the+Y side of slider 10, as is shown in FIG. 6, a pair of movers 22 b(mover 22 b at the +X side is not shown) each consisting of a magnetunit (or a coil unit) is fixed at a predetermined spacing in the X-axisdirection. Although the pair of movers 22 a and the pair of movers 22 bare placed symmetrical, they have a structure similar to each other.

Movers 22 a and 22 b, as is shown in FIGS. 4 to 6, are arranged apredetermined distance apart in the Y-axis direction structuring a partof a frame shaped movable stage 24 rectangular in a planar view, and aresupported in a non-contact manner on an upper surface substantiallyparallel to the XY plane of a pair of plate members 24 a and 24 b eachextending in the X-axis direction. That is, at a lower surface of movers22 a and 22 b (a surface that face plate members 24 a and 24 b,respectively), air bearings (not shown) are provided, respectively, andby a levitation force (static pressure of pressurized air) that theseair bearings generate with respect to plate members 24 a and 24 b,movers 22 a and 22 ba are supported in a non-contact manner from belowby movable stage 24. Note that self-weight of slider 10 to which eachpair of movers 22 a and 22 b are fixed is supported by the levitationforce that the four air bearings 18 generate with respect to surfaceplate 12, as is previously described.

On the upper surface of each of the pair of plate members 24 a and 24 b,as is shown in FIGS. 4 to 6, stators 26 a and 26 b consisting of a coilunit (or a magnet unit) are placed in an area excluding both ends in theX-axis direction.

Electromagnetic interaction between the pair of movers 22 a and stator26 a generates a drive force (electromagnetic force) for driving thepair of movers 22 a in the X-axis direction and a drive force(electromagnetic force) for driving the pair of movers 22 a in theY-axis direction, and electromagnetic interaction between the pair ofmovers 22 b and stator 26 b generates a drive force (electromagneticforce) for driving the pair of movers 22 b in the X-axis direction and adrive force (electromagnetic force) for driving the pair of movers 22 bin the Y-axis direction. That is, the pair of movers 22 a and stator 26a structure an XY linear motor 28A that generates a drive force in theX-axis direction and the Y-axis direction, the pair of movers 22 b andstator 26 b structure an XY linear motor 28B that generates a driveforce in the X-axis direction and the Y-axis direction, and XY linearmotor 28A and XY linear motor 28B structure the first driver 20A thatdrives slider 10 with predetermined strokes in the X-axis direction aswell as finely drive the slider in the Y-axis direction (refer to FIG.8). The first driver 20A can drive slider 10 in the θz direction bymaking the magnitude of each of the drive forces in the X-axis directiongenerated by XY linear motor 28A and XY linear motor 28B different. Thefirst driver 20A is controlled by controller 60 _(i) (refer to FIG. 8).In the embodiment, while the first driver 20A generates not only a driveforce in the X-axis direction but also a drive force in the Y-axisdirection from the relation of structuring a coarse/fine movement drivesystem that drives slider 10 in the Y-axis direction with the firstdriver 20A as well as the second driver to be described later on, thefirst driver 20A does not necessarily have to generate the drive forcein the Y-axis direction.

Movable stage 24 has the pair of plate members 24 a and 24 b and a pairof connecting members 24 c and 24 d placed a predetermined distanceapart in the X-axis direction each extending in the Y-axis direction. Astep section is formed at both ends in the Y-axis direction ofconnecting members 24 c and 24 d. And, in a state where one end and theother end in the longitudinal direction of plate member 24 a are mountedon the step sections at the −Y side of each of the connecting members 24c and 24 d, connecting members 24 c and 24 d and plate member 24 a areintegrated. Also, in a state where one end and the other end in thelongitudinal direction of plate member 24 b are mounted on the stepsections at the +Y side of each of the connecting members 24 c and 24 d,connecting members 24 c and 24 d and plate member 24 b are integrated(refer to FIG. 5B). That is, in this manner the pair of plate members 24a and 24 b is connected with the pair of connecting members 24 c and 24d to structure the frame shaped movable stage 24.

As is shown in FIGS. 4 and 5A, near both ends in the X-axis direction onthe upper surface of base frame 16, a pair of linear guides 27 a and 27b is fixed, extending in the Y-axis direction. Inside one of the linearguides 27 a positioned at the +X side, a stator 25 a (refer to FIG. 5B)of a Y-axis linear motor 29A consisting of a coil unit (or a magnetunit) that covers almost the total length in the Y-axis direction ishoused on the upper surface and a surface near the −X side. Facing theupper surface and the surface near the −X side of linear guide 27 a, amover 23 a is placed consisting of a magnet unit (or coil unit) havingan L-shaped cross sectional surface that structures Y-axis linear motor29A along with stator 25 a. To the lower surface and the surface at the+X side of mover 23 a that face the upper surface and the surface at the−X side of linear guide 27 a, respectively, air bearings are fixed thatblow out pressurized air to the opposing surface. Of the air bearings,especially as the air bearings fixed to the surface at the +X side ofmover 23 a, vacuum preloaded air bearings are used. The vacuum preloadedair bearings maintain a clearance (void, gap) in the X-axis directionbetween mover 23 a and linear guide 27 a at a constant value bybalancing the static pressure of the pressurized air and the vacuumpreload force between the bearing surface and linear guide 27 a. On theupper surface of mover 23 a, a plurality of X guides 19 consisting of,for example, two rectangular solid members, are fixed spaced apart at apredetermined distance in the Y-axis direction. Each of the two X guides19 is engaged in a non-contact manner with a slide member 21 having aninversed U sectional shape that structures a uniaxial guide device alongwith X guide 19. Air bearings are provided at each of the three surfacesof slide member 21 that face X guide 19.

The two slide members 21, as is shown in FIG. 4, are each fixed to thelower surface (surface at the −Z side) of connecting member 24 c.

The other linear guide 27 b positioned at the −X side houses inside astator 25 b of a Y-axis linear motor 29B consisting of a coil unit (or amagnet unit), and is structured similar to linear guide 27 a except forbeing symmetric (refer to FIG. 5B). Facing the upper surface and thesurface near the +X side of linear guide 27 b, a mover 23 b is placedconsisting of a magnet unit (or coil unit) which is symmetric but has anL-shaped cross sectional surface similar to mover 23 a that structuresY-axis linear motor 29B along with stator 25 b. Facing each of the uppersurface and the surface at the +X side of linear guide 27 b, airbearings are fixed to each of the lower surface and the surface at the−X side of mover 23 b, and especially as the air bearings fixed to thesurface at the −X side of mover 23 b, vacuum preloaded air bearings areused. By the vacuum preloaded air bearings, the clearance (void, gap) inthe X-axis direction between mover 23 b and linear guide 27 b is kept ata constant value.

Between the upper surface of mover 23 b and the bottom surface ofconnecting member 24 d, as is previously described, two uniaxial guidedevices are provided which are structured by X guide 19 and slide member21 engaging with X guide 19 in a non-contact manner.

Movable stage 24 is supported from below by movers 23 a and 23 b via twoeach of (a total of four) uniaxial guide devices on the +X side and the−X side, and is movable in the X-axis direction on mover 23 a and 23 b.Therefore, by the first driver 20A previously described, when slider 10is driven in the X-axis direction, reaction force of the drive forceacts on movable stage 24 in which stators 26 a and 26 b are provided andmovable stage 24 moves in a direction opposite to slider 10 according tothe momentum conservation law. That is, the movement of movable stage 24prevents (or effectively suppresses) generation of vibration caused bythe reaction force of the drive force in the X-axis direction to slider10. That is, movable stage 24 functions as a counter mass when slider 10moves in the X-axis direction. However, movable stage 24 does notnecessarily have to function as a counter mass. Note that a counter massmay be provided to prevent (or effectively suppress) generation ofvibration caused by the drive force to drive slider 10 in the Y-axisdirection with respect to movable stage 24, although it is not providedhere in particular since slider 10 only moves finely in the Y-axisdirection with respect to movable stage 24.

Y-axis linear motor 29A generates a drive force (electromagnetic force)that drives mover 23 a in the Y-axis direction by electromagneticinteraction between mover 23 a and stator 25 a, and Y-axis linear motor29B generates a drive force (electromagnetic force) that drives mover 23b in the Y-axis direction by electromagnetic interaction between mover23 b and stator 25 b.

The drive force in the Y-axis direction that Y-axis linear motors 29Aand 29B generate acts on movable stage 24 via two each of the uniaxialguide devices at the +X side and the −X side. This allows slider 10 tobe driven in the Y-axis direction integrally with movable stage 24. Thatis, in the embodiment, movable stage 24, the four uniaxial guidedevices, and the pair of Y-axis linear motors 29A and 29B structure asecond driver 20B (refer to FIG. 8) that drives slider 10 in the Y-axisdirection.

In the embodiment, the pair of Y-axis linear motors 29A and 29B isphysically separated from surface plate 12 and is also separated in avibratory manner by the three vibration isolators 14. Note that linearguides 27 a and 27 b in which stators 25 a and 25 b of the pair ofY-axis linear motors 29A and 29B provided may be structured movable inthe Y-axis direction with respect to base frame 16, so that the linearguides may function as a counter mass when driving slider 10 in theY-axis direction.

Measurement unit 40, as is shown in FIG. 4, has a unit main section 42that has a cutout shaped space 42 a having an opening at a bottomsection formed at a surface on the −Y side, mark detection system MDSpreviously described connected to unit main section 42 in a state wherea base end is inserted into space 42 a, and a connection mechanism 43that connects barrel section 41 at the tip of mark detection system MDSto unit main section 42.

Connection mechanism 43 includes a support plate 44 that supports barrelsection 41 from the back side (the +Y side) via a mounting member (notshown), and a pair of support arms 45 a and 45 b whose one end eachsupports support plate 44 and the other end is each fixed to the bottomsurface of unit main section 42.

In the embodiment, as mark detection system MDS, for example, an FIA(Field Image Alignment) system of an image processing method is usedthat irradiates a broadband detection beam generated in an illuminationlight source such as a halogen lamp on a target mark, picks up an imageof the target mark formed on a light receiving surface by the reflectionlight from the target mark and an image of an index (not shown) (anindex pattern on an index plate provided inside) using an imaging device(such as a CCD), and outputs their imaging signals. The imaging signalsfrom mark detection system MDS are supplied to controller 60 _(i) (referto FIG. 8), via a signal processor 49 (not shown in FIG. 4, refer toFIG. 8). In measurement device 100 _(i), measurement conditions (alsocalled alignment measurement conditions) of marks using mark detectionsystem MDS can be switched (selected) and set. The alignment measurementconditions which are switched (selected) and set includes; irradiatingconditions for irradiating a detection beam on a mark of the detectiontarget, light receiving conditions for receiving light generated fromthe mark, and signal processing conditions for processingphoto-electrically converted signals obtained by receiving the lightgenerated from the mark. The irradiating conditions and light receivingconditions are switched and set by controller 60 _(i) via mark detectionsystem MDS, and the signal processing conditions are switched and set bycontroller 60 _(i) via signal processor 49.

The irradiating conditions which are switched, for example, includes atleast one of; wavelength of the detection light, light amount of thedetection light irradiated on the mark from an optical system that markdetection system MDS has, and NA or σ of the optical system. Also, thelight receiving conditions which are switched includes at least one of;order of diffracted light generated from the mark, and wavelength of thelight generated from the mark.

For example, by selectively setting a filter used in a wavelengthselection mechanism that mark detection system MDS has on an opticalpath of the illumination light from the illumination light source, thewavelength of the detection light (illumination light) can be selected.Also, by controlling setting or state of stop of an illumination fieldstop, an illumination aperture stop, and an image forming aperture stop(e.g., also including an image forming aperture stop equipped with ashielding section of an annular shielding shape used with an annularillumination aperture stop and the like) that mark detection system MDShas, illumination conditions (normal illumination/modifiedillumination), dark field/bright field detection method, numericalaperture N. A., σ and illumination amount of the optical system and thelike can be set and controlled.

Also, the signal processing conditions which are switched and setincludes at least one of; a waveform analysis (waveform processing)algorithm used in signal processor 49, selection of a signal processingalgorithm such as an EGA calculation model and the like, selection ofvarious parameters used in each of the selected signal processingalgorithms.

The FIA system capable of such switching (selecting) and setting ofalignment measurement conditions is disclosed in, for example, U.S.Patent Application Publication No. 2008/0013073 and the like, and an FIAsystem having a similar structure can also be employed in mark detectionsystem MDS of the embodiment. Note that it is also disclosed in the U.S.Patent Application Publication description described above that bychanging the illumination aperture stop from a normal illuminationaperture stop which has a circular transmitting section to anillumination aperture stop having an annular shape transmitting sectionand by further arranging a phase difference plate at a position near animage forming aperture stop in the latter part of image forming aperturestop, the FIA system (alignment sensors) is made to function also as aphase difference microscope type sensor, and a predetermined phasedifference is given to a diffracted light of a predetermined ordergenerated from the mark as one of the light receiving conditions. In theembodiment, mark detection system MDS also is to have an alignmentauto-focus function that adjusts the focal position of the opticalsystems.

Referring back to FIG. 4, a head mounting member 51 having a roughisosceles triangle shape is placed in between barrel section 41 andsupport plate 44. In head mounting member 51, an opening sectionpenetrating in the Y-axis direction in FIG. 4 is formed and barrelsection 41 is attached to (fixed to) support plate 44 via the mountingmember (not shown) inserted in the opening section. Head mounting member51 also has its rear surface fixed to support plate 44. In this manner,barrel section 41 (mark detection system MDS), head mounting member 51,and support plate 44 are integrated with unit main section 42, via thepair of support arms 45 a and 45 b.

Inside unit main section 42, signal processor 49 and the like previouslydescribed are placed that performs processing on the imaging signalsoutput as detection signals from mark detection system MDS, calculatesposition information on the target mark with respect to the detectioncenter, and outputs the information to controller 60 _(i). Unit mainsection 42 is supported from below via a plurality of, e.g., threevibration isolators 48, at three points, on a support frame 46 having aportal shape when viewed from the −Y side installed on base frame 16.Each vibration isolator 48 is an active type vibration isolation system(a so-called AVIS (Active Vibration Isolation System)), and is equippedwith an accelerometer, a displacement sensor (e.g., a capacitivesensor), an actuator (e.g., a voice coil motor), a mechanical dampersuch as an air damper or a hydraulic damper, and the like. Eachvibration isolator 48 can attenuate vibration of relatively highfrequency with the mechanical damper and can also isolate vibration(control vibration) with the actuator. Accordingly, each vibrationisolator 48 can avoid relatively high frequency vibration from travelingbetween support frame 46 and unit main section 42.

Note that mark detection system MDS is not limited to the FIA system,and for example, a diffracted light interference type alignmentdetection system may also be used that irradiates a coherent detectionlight on the subject mark, makes two diffracted lights (e.g., diffractedlights of the same order or diffracted lights diffracted in the samedirection) generated from the target mark interfere with each other, anddetects the interfered light and outputs the detection signals, insteadof the FIA system. Or, the diffracted light interference type alignmentsystem may be used with the FIA system and the two target marks may bedetected simultaneously. Furthermore, as mark detection system MDS, abeam scan type alignment system that scans a measurement beam in apredetermined direction with respect to a target mark while slider 10 ismoved in a predetermined direction may also be used. Also, in theembodiment, while mark detection system MDS has the alignment auto-focusfunction, instead of, or in addition to this, measurement unit 40 may beequipped with a focal position detection system such as a multi-pointfocal position detection system of an oblique incidence method having astructure similar to the one disclosed in, for example, U.S. Pat. No.5,448,332.

The first position measurement system 30, as is shown in FIGS. 5B and 6,is placed within a recess section formed on the upper surface of surfaceplate 12 and has head section 32 fixed to surface plate 12. The uppersurface of head section 32 faces the lower surface of slider 10 (formingsurface of grating RG1). A predetermined clearance (void, gap), e.g., aclearance of several mm, is formed between the upper surface of headsection 32 and the lower surface of slider 10.

The first position measurement system 30, as is shown in FIG. 8, isequipped with an encoder system 33 and a laser interferometer system 35.Encoder system 33 can acquire position information on slider 10, byirradiating a plurality of beams from head section 32 on a measurementsection (forming surface of grating RG1) on the lower surface of slider10 as well as receiving a plurality of return beams (e.g., a pluralityof diffracted beams from grating RG1) from the measurement section onthe lower surface of slider 10. Encoder system 33 includes an X linearencoder 33 x which measures position in the X-axis direction of slider10 and a pair of Y linear encoders 33 ya and 33 yb which measureposition in the Y-axis direction of slider 10. In encoder system 33, ahead of a diffraction interference type is used that has a structuresimilar to the encoder head disclosed in, for example, U.S. PatentApplication Publication No. 2007/288121 and the like (hereinaftershortly written as an encoder head as appropriate). Note that while ahead includes a light source, a light receiving system (including aphotodetector), and an optical system, in the embodiment, of theseparts, only at least the optical system has to be placed inside thehousing of head section 32 facing grating RG1, and at least one of thelight source and the light receiving system may be placed outside of thehousing of head section 32.

In the embodiment, the first position measurement system (encoder system33) has a common detection point for measuring position information inthe X-axis direction and Y-axis direction of slider 10, and controller60 _(i) controls the actuators of the three vibration isolators 14 realtime, so that the position of the detection point within the XY planecoincides with the detection center of mark detection system MDS, forexample, at a nm level. Control of the actuators of these threevibration isolators 14 is performed, based on relative positioninformation between mark detection system MDS (measurement unit 40) andsurface plate 12 measured by the second position measurement system 50.Accordingly, in the embodiment, by using encoder system 33, controller60 _(i) can always perform measurement of position information withinthe XY plane of slider 10 directly under (rear surface side of slider10) the detection center of mark detection system MDS when measuring thealignment marks on wafer W mounted on slider 10. Controller 60 _(i) alsomeasures the rotation quantity in the θz direction of slider 10, basedon a difference between measurement values of the pair of Y linearencoders 33 ya and 33 yb.

Laser interferometer system 35 can acquire position information onslider 10 by making a measurement beam enter the measurement section(the surface on which grating RG1 is formed) on the lower surface ofslider 10, and also receiving the return beam (e.g., reflection lightfrom a surface on which grating RG1 is formed). Laser interferometersystem 35, for example, makes four measurement beams enter the lowersurface of slider 10 (the surface on which grating RG1 is formed). Laserinterferometer system 35 is equipped with laser interferometers 35 a to35 d (refer to FIG. 8) that irradiate these four measurement beams,respectively. In the embodiment, four Z heads are structured by laserinterferometers 35 a to 35 d. Note that the measurement beams from eachof the laser interferometers 35 a to 35 d are irradiated on positions ateach vertex of a square having two sides parallel to the X-axis and twosides parallel to the Y-axis on the lower surface (a surface on whichgrating RG1 is formed) of slider 10, whose center is the detectioncenter of encoder system 33.

In the embodiment, the surface on which grating RG1 is formed alsofunctions as a reflection surface of each measurement beam from laserinterferometer system 35. Controller 60 _(i) measures information on theposition in the Z-axis direction and the rotation quantity in the θxdirection and the θy direction of slider 10, using laser interferometersystem 35. Note that as it is obvious from the description above,although slider 10 is not positively driven by drive system 20previously described with respect to surface plate 12 in the Z-axis, theθx and the θy directions, because slider 10 is supported by levitationon surface plate 12 by the four air bearings placed at the four cornersof the bottom surface, the position of slider 10 actually changes onsurface plate 12 in each of the Z-axis, the θx and the θy directions.That is, slider 10 is actually movable with respect to surface plate 12in each of the Z-axis, the θx and the θy directions. Displacement ineach of the θx and θy directions in particular causes a measurementerror (Abbe error) in encoder system 33. Taking such points intoconsideration, position information in each of the Z-axis, the θx andthe θy directions of slider 10 is measured by the first positionmeasurement system 30 (laser interferometer system 35).

Note that for measurement of information on position in the Z-axisdirection and the rotation quantity in the θx direction and the θydirection of slider 10, since the beams only have to be incident onthree different points on the surface where grating RG1 is formed, the Zheads, e.g., laser interferometers, that are required should be three.Note that a cover glass to protect grating RG1 can be provided on thelower surface of slider 10, and on the surface of the cover glass, awavelength selection filter may be provided that allows each measurementbeam from encoder system 33 to pass and prevents each measurement beamfrom laser interferometer system 35 from passing.

As it can be seen from the description so far, controller 60 _(i) canmeasure the position in directions of six degrees of freedom of slider10 by using encoder system 33 and laser interferometer system 35 of thefirst position measurement system 30. In this case, in encoder system33, influence of air fluctuation can almost be ignored since the opticalpath lengths of all measurement beams in the air are extremely short,and optical path lengths of the pair of measurement beams irradiated ongrating RG1 from X head 73 x, optical path lengths of the pair ofmeasurement beams irradiated on grating RG1 from Y head 37 ya, andoptical path lengths of the pair of measurement beams irradiated ongrating RG1 from Y head 37 yb are almost equal with each other.Accordingly, position information within the XY plane (including the θzdirection) of slider 10 can be measured with high precision by encodersystem 33. Also, because the substantial detection point on grating RG1in the X-axis direction and the Y-axis direction by encoder system 33and the detection point on the lower surface of slider 10 in the Z-axisdirection by laser interferometer system 35 each coincide with thedetection center of mark detection system MDS within the XY plane,generation of the so-called Abbe error which is caused by shift withinthe XY plane between the detection point and the detection center ofmark detection system MDS can be suppressed to a level that can beignored. Accordingly, controller 60 _(i) can measure the position in theX-axis direction, the Y-axis direction, and the Z-axis direction ofslider 10 without Abbe error caused by shift in the XY plane between thedetection point and the detection center of mark detection system MDSwith high precision by using the first position measurement system 30.

However, for the Z-axis direction parallel to optical axis AX1 of markdetection system MDS, position information in the XY plane of slider 10is not necessarily measured at a position at the surface of wafer W byencoder system 33, that is, the Z position of the placement surface ofgrating RG1 and the surface of wafer W do not necessarily coincide.Therefore, in the case grating RG1 (that is, slider 10) is inclined withrespect to the XY plane, when slider 10 is positioned based onmeasurement values of each of the encoders of encoder system 33, as aresult, a positioning error (a kind of Abbe error) corresponding to theinclination with respect to the XY plane of grating RG1 occurs due to aZ position difference ΔZ (that is, position displacement in the Z-axisdirection between the detection point by encoder system 33 and thedetection center (detection point) by mark detection system MDS) betweenthe placement surface of grating RG1 and the surface of wafer W.However, this positioning error (position control error) can be acquiredby a simple calculation by using difference ΔZ, pitching quantity θx,and rolling quantity θy, and using this as an offset and by setting theposition of slider 10 based on position information after correction inwhich measurement values of (each encoder of) encoder system 33 arecorrected by the offset amount, the kind of Abbe error described aboveno longer affects the measurement. Or, instead of correcting themeasurement values of (each encoder of) encoder system 33, one or aplurality of information for moving the slider such as a target positionto where slider 10 should be positioned may be corrected, based on theabove offset.

Note that in the case grating RG1 (that is, slider 10) is inclined withrespect to the XY plane, head section 32 may be moved so that apositioning error due to the inclination does not occur. That is, in thecase an inclination has been measured in grating RG1 (that is, slider10) with respect to the XY plane by the first position measurementsystem 30 (e.g., laser interferometer system 35), surface plate 12 thatholds head section 32 may be moved, based on position informationacquired using the first position measurement system 30. Surface plate12, as is described above, can be moved using vibration isolators 14.

Also, in the case grating RG1 (that is, slider 10) is inclined withrespect to the XY plane, position information on the mark acquired usingmark detection system MDS may be corrected, based on the positioningerror caused by the inclination.

The second position measurement system 50, as is shown in FIGS. 4, 5A,and 5B, has a pair of head sections 52A and 52B provided at the lowersurface of one end and the other end in the longitudinal direction ofhead mounting member 51 previously described, and scale members 54A and54B that are placed facing head sections 52A and 52B. The upper surfaceof scale members 54A and 54B is to be the same height as the surface ofwafer W held by wafer holder WH. On each of the upper surfaces of scalemembers 54A and 54B, reflection type two-dimensional gratings RG2 a andRG2 b are formed. Two-dimensional gratings (hereinafter shortly referredto as gratings) RG2 a and RG2 b both include a reflective diffractiongrating (X diffraction grating) whose periodic direction is in theX-axis direction and a reflective diffraction grating (Y diffractiongrating) whose periodic direction is in the Y-axis direction. The pitchbetween the grid lines of the X diffraction grating and the Ydiffraction grating is set to, for example, 1 μm.

Scale members 54A and 54B consist of a material having a low thermalexpansion, e.g., a zero thermal expansion material, and are each fixedon surface plate 12 via support members 56, as is shown in FIGS. 5A and5B. In the embodiment, dimensions of scale members 54A and 54B andsupport members 56 are decided so that gratings RG2 a and RG2 b facehead sections 52A and 52B with a gap of around several mm in between.

As is shown in FIG. 7, one head section 52A fixed to the lower surfaceat the end on the +X side of head mounting member 51 includes an XZ head58X₁ whose measurement direction is in the X-axis and the Z-axisdirections and a YZ head 58Y₁ whose measurement direction is in theY-axis and the Z-axis directions housed in the same housing. XZ head58X₁ (to be more accurate, an irradiation point on grating RG2 a of themeasurement beam emitted by XZ head 58X₁) and YZ head 58Y₁ (to be moreaccurate, an irradiation point on grating RG2 a of the measurement beamemitted by YZ head 58Y₁) are placed on the same straight line parallelto the Y-axis.

The other head section 52B is placed symmetric to head section 52A withrespect to a straight line (hereinafter called a reference axis) LVwhich passes through optical axis AX1 of mark detection system MDS andis parallel to the Y-axis, however, the structure is similar to that ofhead section 52A. That is, head section 52B has XZ head 58X₂ and YZ head58Y₂ placed symmetric to XZ head 58X₁ and YZ head 58Y₁ with respect toreference axis LV, and the irradiation points of the measurement beamsirradiated on grating RG2 b from each of the XZ head 58X₂ and YZ head58Y₂ set on the same straight line parallel to the Y-axis

Head sections 52A and 52B structure an XZ linear encoder which measuresposition in the X-axis direction (X position) and position in the Z-axisdirection (Z position) of gratings RG2 a and RG2 b and a YZ linearencoder which measures position in the Y-axis direction (Y position) andZ position, using scale members 54A and 54B, respectively. Gratings RG2a and RG2 b, here, are formed on the upper surface of scale members 54Aand 54B which are each fixed on surface plate 12 via support members 56,and head sections 52A and 52B are provided at head mounting member 51which is integral with mark detection system MDS. As a result, headsections 52A and 52B measure the position (positional relation betweenmark detection system MDS and surface plate 12) of surface plate 12 withrespect to mark detection system MDS. In the description below, for thesake of convenience, XZ linear encoder and YZ linear encoder will bedescribed as XZ linear encoders 58X₁ and 58X₂ and YZ linear encoders58Y₁ and 58Y₂ (refer to FIG. 8), using the same reference code as XZheads 58X₁ and 58X₂ and YZ heads 58Y₁ and 58Y₂.

In the embodiment, XZ linear encoder 58X₁ and YZ linear encoder 58Y₁structure a four-axis encoder 58 ₁ (refer to FIG. 8) that measuresposition information in each of the X-axis, the Y-axis, the Z-axis, andthe θx directions with respect to mark detection system MDS of surfaceplate 12. Similarly, XZ linear encoder 58X₂ and YZ linear encoder 58Y₂structure a four-axis encoder 58 ₂ (refer to FIG. 8) that measuresposition information in each of the X-axis, the Y-axis, the Z-axis, andthe θx directions with respect to mark detection system MDS of surfaceplate 12. In this case, position information in the θy direction ofsurface plate 12 with respect to mark detection system MDS is obtained(measured), based on position information in the Z-axis direction withrespect to mark detection system MDS of surface plate 12 measured byeach of the four-axis encoders 58 ₁ and 58 ₂, and position informationin the θz direction of surface plate 12 with respect to mark detectionsystem MDS is obtained (measured), based on position information in theY-axis direction with respect to mark detection system MDS of surfaceplate 12 measured by each of the four-axis encoders 58 ₁ and 58 ₂.

Accordingly, four-axis encoder 58 ₁ and four-axis encoder 58 ₂ structurethe second position measurement system 50 which measures positioninformation in directions of six degrees of freedom of surface plate 12with respect to mark detection system MDS, namely, measures informationon relative position in directions of six degrees of freedom betweenmark detection system MDS and surface plate 12. The information onrelative position in directions of six degrees of freedom between markdetection system MDS and surface plate 12 measured by the secondposition measurement system 50 is supplied at all times to controller 60_(i), and based on this information on relative position, controller 60_(i) controls the actuators of the three vibration isolators 14 realtime so that the detection point of the first position measurementsystem 30 is in a desired position relation with respect to thedetection center of mark detection system MDS, or to be more specific,the position in the XY plane of the detection point of the firstposition measurement system 30 coincides with the detection center ofmark detection system MDS such as at a nm level, and the surface ofwafer W on slider 10 also coincides with the detection position of markdetection system MDS. Note that if the detection point of the firstposition measurement system 30 can be controlled to be in a desiredposition relation with respect to the detection center of mark detectionsystem MDS, the second position measurement system 50 does not have tomeasure the information on relative position in all directions of sixdegrees of freedom.

As is obvious from the description on the first position measurementsystem 30 described earlier and the description on the second positionmeasurement system 50, in measurement device 100 _(i), the firstposition measurement system 30 and the second position measurementsystem 50 structure a position measurement system that measures positioninformation in directions of six degrees of freedom of slider 10 withrespect to mark detection system MDS.

FIG. 8 shows a block diagram of an input output relation of controller60 _(i) which mainly structures a control system of each measurementdevice 100 _(i) (i=1 to 3) of measurement system 500 ₁ (and a controlsystem of each measurement device 100 _(i) (i=4 to 6 of measurementsystem 500 ₂). Controller 60 _(i) includes a workstation (or amicrocomputer) or the like, and has overall control over each part thatstructures measurement device 100 _(i). As is shown in FIG. 8,measurement device 100 _(i) is equipped with wafer carrying system 70_(i) that has a part of the system placed inside a chamber along withcomponent parts shown in FIG. 4. Wafer carrying system 70 _(i), as ispreviously described, consists of, for example, a horizontal multi-jointarm robot.

Measurement system 500 ₂, which is structured similarly to measurementsystem 500 ₁ described above, is equipped with; a chamber similar tochamber 502 where the three measurement devices 100 _(i) (i=4 to 6) anda carry system 521 are housed, and the EFEM system arranged at one sideof the chamber.

In the embodiment, as is obvious from FIG. 1, while measurement system500 ₂ is not connected in-line with exposure apparatus 200 and C/D 300similarly to measurement system 500 ₁, measurement system 500 ₂ may beconnected in-line to at least one of exposure apparatus 200 and C/D 300.In the embodiment, although it is omitted in the drawings, a track railfor OHT is provided near the ceiling of the clean room directly abovethe three loading ports 514 of EFEM system 510 of measurement system 500₂. The OHT carries in FOUP 520 onto loading port 514. Also, each of thethree measurement devices 100 _(i) (i=4 to 6) that measurement system500 ₂ is equipped with is structured similarly to measurement devices100 _(i) (i=1 to 3) described earlier.

Exposure apparatus 200, as an example, is a projection exposureapparatus (scanner) of a step-and-scan method. FIG. 9 shows the insideof the chamber of exposure apparatus 200, with component parts partlyomitted.

Exposure apparatus 200, as is shown in FIG. 9, is equipped with anillumination system IOP, a reticle stage RST that holds a reticle R, aprojection unit PU that projects an image of a pattern formed on reticleR on wafer W coated with a sensitive agent (resist), a wafer stage WSTthat moves within the XY plane holding wafer W, a control system forthese parts and the like. Exposure apparatus 200 is equipped with aprojection optical system PL that has an optical axis AX parallel to theZ-axis direction.

Illumination system IOP includes a light source, and an illuminationoptical system connected to the light source via a light transmittingoptical system, and illuminates a slit shaped illumination area IAR set(limited) by a reticle blind (masking system) on reticle R extendingnarrowly in the X-axis direction (orthogonal direction of the pagesurface in FIG. 9) with an almost uniform illuminance. The structure ofillumination system IOP is disclosed in, for example, U.S. PatentApplication Publication No. 2003/0025890 and the like. Here, asillumination light IL, an ArF excimer laser beam (wavelength 193 nm) isused as an example.

Reticle stage RST is arranged below illumination system IOP in FIG. 9.Reticle stage RST can be finely moved within a horizontal plane (XYplane) on a reticle stage surface plate not shown by a reticle stagedrive system 211 (not shown in FIG. 9, refer to FIG. 10) which includesa linear motor and the like, and can also be moved in predeterminedstrokes in a scanning direction (the Y-axis direction which is thelateral direction within the page in FIG. 9).

On reticle stage RST, reticle R is mounted that has a pattern areaformed on a surface on the −Z side (pattern surface) and a plurality ofmarks formed whose positional relation with the pattern area is known.Position information (including rotation information in the θzdirection) within the XY plane of reticle stage RST is constantlydetected by a reticle laser interferometer (hereinafter referred to as“reticle interferometer”) 214 via a movable mirror 212 (or a reflectionsurface formed on an end surface of reticle stage RST), for example, ata resolution of around 0.25 nm. Measurement information on reticleinterferometer 214 is supplied to exposure controller 220 (refer to FIG.10). Note that measurement of the position information within the XYplane of reticle stage RST described above may be performed by anencoder, instead of reticle interferometer 214.

Projection unit PU is arranged below reticle stage RST in FIG. 9.Projection unit PU includes a barrel 240, and projection optical systemPL held within barrel 240. Projection optical system PL, for example, isdouble telecentric, and has a predetermined projection magnification(e.g., ¼ times, ⅕ times, ⅛ times or the like). Reticle R is arranged sothat its pattern surface almost coincides with a first surface (objectplane) of projection optical system PL, and wafer W whose surface iscoated with a resist (sensitive agent) is arranged on a second surface(image plane) side of projection optical system PL. Therefore, whenillumination area IAR on reticle R is illuminated with illuminationlight IL from illumination system IOP, illumination light IL havingpassed through reticle R forms a reduced image (a reduced image of apart of the circuit pattern) of the circuit pattern of reticle R withinillumination area IAR on an area (hereinafter also called an exposurearea) IA on wafer W conjugate with illumination area IAR, via projectionoptical system PL. Then, by reticle stage RST and wafer stage WST beingsynchronously driven, reticle R is relatively moved in the scanningdirection (the Y-axis direction) with respect to illumination area IAR(illumination light IL) and wafer W is relatively moved in the scanningdirection (the Y-axis direction) with respect to exposure area IA(illumination light IL), so that scanning exposure of a shot area(divided area) on wafer W is performed and the pattern of reticle R istransferred onto the shot area.

As projection optical system PL, as an example, a refraction system isused consisting of a plurality of only refraction optical elements (lenselements), e.g., around 10 to 20, arranged along optical axis AXparallel to the Z-axis direction. Of the plurality of lens elementsstructuring projection optical system PL, the plurality of lens elementson the object surface side (reticle R side) is a movable lens that canbe shifted in the Z-axis direction (the optical axis direction ofprojection optical system PL) and is movable in a tilt direction (thatis, the θx direction and the θy direction) with respect to the XY plane,by driving elements not shown, such as, for example, a piezoelectricelement and the like. Then, by an image forming characteristiccorrection controller 248 (not shown in FIG. 9, refer to FIG. 10)independently adjusting applied voltage with respect to each drivingelement based on instructions from exposure controller 220, each of themovable lenses is moved individually so that various image formingcharacteristics (magnification, distortion aberration, astigmatism, comaaberration, curvature of field and the like) are to be adjusted. Notethat instead of, or in addition to moving the movable lenses, astructure may be employed in which an airtight chamber is provided inbetween specific lens elements which are adjacent inside barrel 240, andthe pressure of gas inside the airtight chamber is controlled by imageforming characteristic correction controller 248, or a structure may beemployed in which a center wavelength of illumination light IL can beshifted by image forming characteristic correction controller 248. Suchstructures may also allow the image forming characteristics ofprojection optical system PL to be adjusted.

Wafer stage WST is moved on a wafer stage surface plate 222 inpredetermined strokes in the X-axis direction and the Y-axis directionby a stage drive system 224 (indicated as a block for convenience inFIG. 9) which includes a planar motor, a linear motor or the like, andis also finely moved in the Z-axis direction, the θx direction, the θydirection, and the θz direction. On wafer stage WST, wafer W is held byvacuum chucking or the like via a wafer holder (not shown). In theembodiment, the wafer holder is to be able to hold a 300 mm wafer bysuction. Note that, instead of wafer stage WST, a stage device can beused that is equipped with a first stage which moves in the X-axisdirection, the Y-axis direction and the θz direction, and a second stagewhich finely moves in the Z-axis direction, the θx direction, and the θydirection on the first stage. Note that one of wafer stage WST and thewafer holder of wafer stage WST or both may be called “a secondsubstrate holding member.”

Position information (including rotation information (yawing amount(rotation amount θz in the θz direction), pitching amount (rotationamount θx in the θx direction), and rolling amount (rotation amount θyin the θy direction)) within the XY plane of wafer stage WST isconstantly detected by a laser interferometer system (hereinaftershortly referred to as interferometer system) 218 via a movable mirror216 (or a reflection surface formed on an end surface of wafer stageWST) at a resolution of, for example, around 0.25 nm. Note thatmeasurement of the position information within the XY plane of waferstage WST may be performed by an encoder system, instead ofinterferometer system 218.

Measurement information on interferometer system 218 is supplied toexposure controller 220 (refer to FIG. 10). Exposure controller 220controls the position (including rotation in the θz direction) withinthe XY plane of wafer stage WST via stage drive system 224, based onmeasurement information on interferometer system 218.

Also, although it is omitted in FIG. 9, position in the Z-axis directionand tilt amount of the surface of wafer W is measured by a focus sensorAFS (refer to FIG. 10) consisting of a multi-point focal point detectionsystem of an oblique incidence method disclosed in, for example, U.S.Pat. No. 5,448,332 and the like. Measurement information on this focussensor AFS is also supplied to exposure controller 220 (refer to FIG.10).

Also, on wafer stage WST, a fiducial plate FP is fixed whose surface isat the same height as the surface of wafer W. On the surface of thisfiducial plate FP, a first fiducial mark used for base line measurementand the like of an alignment detection system AS and a pair of secondfiducial marks detected with a reticle alignment detection system to bedescribed later on are formed.

On a side surface of barrel 240 of projection unit PU, alignmentdetection system AS is provided that detects alignment marks formed onwafer W or the first fiducial mark. As alignment detection system AS, asan example, an FIA (Field Image Alignment) system is used, which is akind of an image forming alignment sensor of an image processing methodthat measures a mark position by irradiating a broadband (wide band)light such as a halogen lamp on a mark and performing image processingon an image of this mark. Note that instead of alignment detectionsystem AS of the image processing method, or along with alignmentdetection system AS, a diffracted light interference type alignmentsystem may also be used.

In exposure apparatus 200, furthermore above reticle stage RST, a pairof reticle alignment detection systems 213 (not shown in FIG. 9, referto FIG. 10) that can simultaneously detect a pair of reticle marks atthe same Y position on reticle R mounted on reticle stage RST isprovided spaced apart by a predetermined distance in the X-axisdirection. Detection results of the marks by reticle alignment detectionsystem 213 are supplied to exposure controller 220.

FIG. 10 shows an input output relation of exposure controller 220 in ablock diagram. As is shown in FIG. 10, other than each of the componentsdescribed above, exposure apparatus 200 is equipped with a wafercarrying system 270 and the like that carries the wafers, connected toexposure controller 220. Exposure controller 220 includes amicrocomputer, a workstation or the like, and has overall control overthe whole apparatus including each of the components described above.Wafer carrying system 270, for example, consists of a horizontalmulti-joint arm robot.

Referring back to FIG. 1, although it is omitted in the drawing, C/D 300is equipped with, for example, a coating section in which coating of asensitive agent on a wafer is performed, a developing section in whichthe wafer can be developed, a baking section that performs pre-bake (PB)and pre-develop bake (post-exposure bake: PEB), and a wafer carryingsystem (hereinafter referred to as a C/D inner carrying system for thesake of convenience). C/D 300 is furthermore equipped with a temperaturecontrolling section 330 that can control the temperature of the wafer.Temperature controlling section 330 is normally a cooling section, andis equipped, for example, with a flat plate (temperature controllingdevice) called a cool plate. The cool plate is cooled, for example, bycirculating cooling water. Other than this, thermoelectric cooling bythe Peltier effect may be used in some cases.

Analysis device 3000 performs various analyses and operations, inaccordance with instructions from host computer 2000. In one example,analysis device 3000, for example, performs an operation according to apredetermined program, based on measurement results of overlaydisplacement acquired, for example, in the manner described later on bymeasurement system 500 ₂, and calculates correction values which are tobe fed back to exposure apparatus 200.

In substrate processing system 1000 according to the embodiment,exposure apparatus 200 and C/D 300 both are equipped with a bar codereader (not shown), and while wafers are being carried by each of wafercarrying system 270 (refer to FIG. 10) and the C/D inner carrying system(not shown), the bar code reader appropriately reads identificationinformation on each wafer, such as wafer number, lot number and thelike. In the description below, to simplify the explanation, descriptionrelated to reading the identification information for each wafer usingthe bar code reader is to be omitted.

Next, in the three measurement devices 100 ₁ to 100 ₃ of one of themeasurement devices 500 ₁, an operation of each measurement device 100_(i) when concurrently processing a plurality of wafers (e.g., 25 piecesof wafers) included in the same lot is to be described, based on aflowchart in FIG. 11 that corresponds to a processing algorithm ofcontroller 60 _(i) of measurement device 100 _(i). Here, as an example,of the 25 pieces of wafer in the same lot, measurement device 100 ₁ isto be in charge of measurement processing of 9 pieces, measurementdevice 100 ₂ is to be in charge of 8 pieces, and measurement device 100₃ is to be in charge of 8 pieces. Note that the plurality of pieces (25pieces) of wafers in the same lot may be apportioned to two measurementdevices of measurement device 100 ₁, measurement device 100 ₂, andmeasurement device 100 ₃. Also, as is described above, the plurality ofpieces of wafers included in the same lot may, or may not be apportionedequally.

As a premise, wafer W serving as a measurement target of measurementdevice 100 _(i) (i=1 to 3) is to be a 300=wafer, and a wafer on whichprocessing (such as etching, oxidation/diffusion, ion implantation, andflattening (CMP)) in the pre-process of wafer processing has beenapplied, and a wafer which is not yet coated by a resist. On wafer Wserving as a measurement target, by exposure performed earlier on theprevious layers, a plurality of, e.g., I (as an example, I=98) dividedareas called shot areas (hereinafter called shots) are formed arrangedin a matrix shape, and on street lines surrounding each shot or streetlines inside each shot (in the case a plurality of chips are made in oneshot), a plurality of types of marks, such as search alignment marks(search marks) for search alignment, wafer alignment marks (wafer marks)for fine alignment and the like are to be provided. The plurality oftypes of marks is formed, along with the shots. In the embodiment, assearch marks and wafer marks, two-dimensional marks are to be used.

Also, by an operator of measurement device 100 _(i), informationnecessary for alignment measurement to wafer W is to be input in advancevia an input device (not shown) and stored in a memory of controller 60_(i). Here, the information necessary for alignment measurement includesvarious information such as, thickness information on wafer W, flatnessinformation on wafer holder WH, and design information on shots and onarrangement of alignment marks on wafer W.

Processing corresponding to the flowchart in FIG. 11 described below isperformed by the three measurement devices 100 ₁ to 100 ₃, concurrentlyand individually.

A processing algorithm corresponding to a flowchart in FIG. 11 starts,for example, when the operator or host computer 2000 instructs themeasurement to be started. On this operation, of the 25 pieces of wafersincluded in one lot, the pieces of wafers that each of the measurementdevices is in charge are to be housed within a wafer carrier at apredetermined position inside chamber 101 _(i) of measurement device 100_(i). Other than this, concurrently with the measurement processing bythe three measurement devices 100 _(i), each of the wafers of the onelot may be carried sequentially into measurement device 100 _(i). Forexample, under the control of measurement system controller 530 ₁ thatcontrols robot 516, carrying member 524 and carrying member 526 and thelike, for example, 25 pieces of wafers included in one lot inside apredetermined FOUP 520 may be taken out one by one sequentially by robot516, and then be sequentially carried to a predetermined deliveryposition between each of the three measurement devices 100 _(i) bycarrying member 524. In this case the processing algorithm correspondingto the flowchart in FIG. 11 starts when measurement system controller530 ₁ gives instructions to each of the controllers 60 i and robot 516to start carriage.

Note that, in the case exposure apparatus 200 and measurement system 500₁ are connected, instructions for starting measurement may be given fromexposure controller 220 of exposure apparatus 200 to measurement systemcontroller 530 ₁, without going through host computer 2000.

Note that measurement device 100 _(i) is equipped with a bar code reader(not shown) similarly to exposure apparatus 200 and C/D 300, andidentification information on each wafer, e.g., wafer number, lot numberand the like, is appropriately read by the bar code reader during thecarriage of the wafer by wafer carrying system 70 _(i) (refer to FIG.8). In the description below, to simplify the explanation, descriptionrelated to reading the identification information for each wafer usingthe bar code reader is to be omitted. Note that each of the measurementdevices 100 _(i) does not have to be equipped with the bar code reader.For example, the bar code reader may be arranged in carrying system 521.

First of all, in step S102, a count value i of a counter that shows thenumber of a measurement target wafer in a lot is initialized to 1 (i←1).

In the next step, S104, wafer W is loaded onto slider 10. This loadingof wafer W is performed by wafer carrying system 70 _(i) and thevertical movement member on slider 10, under the control of controller60 _(i). Specifically, wafer W is carried from the wafer carrier (or thedelivery position) to an area above slider 10 at the loading position bywafer carrying system 70 _(i), and then by the vertical movement memberbeing moved upward by a predetermined amount by driver 13, wafer W isdelivered to the vertical movement member. Then, after wafer carryingsystem 70 _(i) has been withdrawn from above slider 10, by the verticalmovement member being moved downward by driver 13, wafer W is mounted onwafer holder WH on slider 10. Then, vacuum pump 11 is turned on, so thatwafer W loaded on slider 10 is vacuum chucked at wafer holder WH. Notethat in the case each of the plurality of wafers included in one lot issequentially carried into measurement device 100 _(i) concurrently withthe measurement processing by measurement device 100 _(i), prior to theloading of the wafer described above, the plurality of wafers in thepredetermined FOUP 520 is taken out one by one, sequentially by robot516, and the wafers are delivered to carrying member 524 by robot 516and then carried by carrying member 524 to a predetermined deliveryposition between measurement device 100 _(i) to be delivered to wafercarrying system 70 _(i).

In the next step, S106, position (Z position) in the Z-axis direction ofwafer W is adjusted. Prior to this adjustment of the Z position,controller 60 _(i) controls the internal pressure (drive force in theZ-axis direction that vibration isolator 14 generates) of the air mountsof the three vibration isolators 14 based on relative positioninformation between mark detection system MDS and surface plate 12regarding the Z-axis direction, the θy direction, and the θx directionmeasured by the second position measurement system 50, and surface plate12 is set so that its upper surface becomes parallel to the XY plane andthe Z position is at a predetermined reference position. Wafer W isconsidered to have uniform thickness. Accordingly, in step S106,controller 60 _(i) moves surface plate 12 in the Z-axis direction andadjusts the Z position of the surface of wafer W, by adjusting the driveforce in the Z-axis direction that the three vibration isolators 14generates, such as the internal pressure (amount of compressed air) ofthe air mounts, so that the surface of wafer W is set within a range inwhich focal position of the optical system is adjustable by theauto-focus function of mark detection system MDS, based on thicknessinformation on wafer W in the memory. Note that controller 60 _(i) mayperform adjustment of the Z position of the wafer surface based ondetection results (output) of the focal position detection system in thecase measurement unit 40 is equipped with a focal position detectionsystem. For example, mark detection system MDS may be equipped with afocal position detection system that detects position in the Z-axisdirection of the surface of wafer W via an optical element (objectiveoptical element) at the tip. Also, the adjustment of the Z position ofthe surface of wafer W based on the detection results of the focalposition detection system can be performed by moving slider 10 alongwith surface plate 12, which is moved using vibration isolators 14. Notethat a drive system 20 having a structure that can move in slider 10 notonly in a direction within the XY plane but also in the Z-axisdirection, the θx direction, and the θy direction may be employed, anddrive system 20 may be used to move slider 10. Note that Z positionadjustment of the wafer surface may include tilt adjustment of the wafersurface. By using drive system 20 to adjust tilt of the wafer surface,in the case an error (a kind of Abbe error) caused by a difference ΔZ ofthe Z position between the placement surface of grating RG1 and thesurface of wafer W, at least one of the measures described above shouldbe performed.

In the next step, S108, search alignment of wafer W is performed, undera measurement condition setting of a search mark determined in advance.The measurement condition of the search mark may be the same conditionas a first condition set in step S110 to be described later on, or ameasurement condition more suitable for search mark measurement takinginto consideration the difference between a wafer mark and a searchmark.

In search alignment, for example, at least two search marks positionedin peripheral sections almost symmetrical to the center of wafer W aredetected using mark detection system MDS. Controller 60 _(i) controlsmovement of slider 10 by drive system 20, and while positioning each ofthe search marks within a detection area (detection field) of markdetection system MDS, acquires measurement information by the firstposition measurement system 30 and measurement information by the secondposition measurement system 50, and obtains position information on eachsearch mark, based on detection signals when the search marks formed onwafer W is detected using mark detection system MDS and measurementinformation by the first position measurement system 30 (or measurementinformation by the second position measurement system 50).

Here, measurement of search marks is performed by irradiating abroadband light (detection light) on a search mark from the opticalsystem of mark detection system MDS, and receiving the light generatedfrom the search mark, which is a light of a predetermined wavelength(detection wavelength) and a diffracted light of a predetermined order(e.g. ±1^(st) order), by a detector, and processing thephoto-electrically converted signals according to a predetermined signalprocessing condition.

Controller 60 _(i) obtains position coordinates on a referencecoordinate system of the two search marks, based on detection results ofmark detection system MDS (relative positional relation between thedetection center (index center) of mark detection system MDS obtainedfrom processing the photo-electrically converted signals described aboveunder the signal processing condition described above) output fromsignal processor 49 and measurement values of the first positionmeasurement system 30 (and measurement values of the second positionmeasurement system 50) at the time of detection of each search mark.Here, the reference coordinate system is to be an orthogonal coordinatesystem set by measurement axes of the first position measurement system30.

Thereafter, a residual rotation error of wafer W is calculated from theposition coordinates of the two search marks, and slider 10 is finelyrotated so that this rotation error becomes almost zero. This completesthe search alignment of wafer W. Note that since wafer W is actuallyloaded on slider 10 in a state where pre-alignment has been performed,the center position displacement of wafer W is small enough to beignored, and the residual rotation error is extremely small.

In the next step, S110, a first condition instructed from measurementsystem controller 530 ₁ is set as the measurement condition (alignmentmeasurement condition) of a mark including at least one of anirradiating condition for irradiating a detection beam on the mark, alight receiving condition for receiving light generated from the mark,and a signal processing condition for processing a photo-electricallyconverted signal obtained by receiving the light generated from themark.

In step S110, at least one of an irradiating condition, alight receivingcondition, and a signal processing condition that is switchable andsuitable for detection of the wafer mark is set as the first condition.Here, as an example of the first condition, for example, optimization isto be performed of the wavelength of the illumination light in markdetection system MDS. Also, as an example, here, the wafer mark formedon wafer W subject to processing is a mark formed on the outermost layerof pattern layers (layers) laminated on wafer W, and to observe this,the wavelength of a specific observation light does not have to bespecified, and a broadband white light generated by an illuminationlight source such as a halogen lamp may be used for observation.Accordingly, controller 60 _(i) performs setting (control) of thewavelength selection mechanism, so that a filter that transmits a lightbeam (white light) having a wavelength of 530 to 800 nm in thewavelength selection mechanism of mark detection system MDS is to beselected.

In the next step S112, alignment measurement on all wafers (full-shotone point measurement, or in other words, full-shot EGA measurement) isperformed under the setting of the first condition, that is, one wafermark is measured for each of the 98 shots. Specifically, controller 60_(i) obtains position coordinates on the reference coordinate system ofwafer marks on wafer W, that is, position coordinates of the shots,similarly to the measurement of position coordinates of each searchalignment mark at the time of search alignment described earlier.However, in this case, by irradiating the wafer mark with detectionlight of a broadband wavelength determined by the first condition, viathe optical system of mark detection system MDS, at a light amount of adefault setting in a conventional illumination condition (σ value),receiving a diffracted light of a predetermined order (e.g., ±1^(st)order) generated from the wafer mark by a detector, and processing thephoto-electrically converted signal according to a signal processingcondition (processing algorithm) of a default setting, detection resultsof the mark used to calculate position coordinates on a referencecoordinate system of the wafer mark on wafer W can be obtained.

However, in this case, different from the time of search alignment,measurement information of the second position measurement system 50 isused without exception when calculating position coordinates of theshots. The reason, as is described earlier, is that controller 60 _(i)controls the actuators of the three vibration isolators 14 real timebased on measurement information of the second position measurementsystem 50, so that position within the XY plane of detection points ofthe first position measurement system 30 coincides with the detectioncenter of mark detection system MDS, for example, at a nm level, andalso the surface of wafer W on slider 10 coincides with the detectionposition of mark detection system MDS. However, at the time of detectionof the wafer marks, since there is no assurance that the position withinthe XY plane of the detection points of the first position measurementsystem 30 coincides with the detection center of mark detection systemMDS at, for example, a nm level, it is necessary to calculate theposition coordinates of the shots, taking into consideration positiondisplacement between the detection point and the detection center as anoffset. For example, by correcting the detection results of markdetection system MDS or the measurement values of the first positionmeasurement system 30 using the offset described above, positioncoordinates on the reference coordinate system of the wafer marks onwafer W to be calculated can be corrected.

Here, on this full-shot one point measurement, controller 60 _(i) movesslider 10 (wafer W) in a direction in at least one of the X-axisdirection and the Y-axis direction via drive system 20 based onmeasurement information on the first position measurement system 30 andmeasurement information on the second position measurement system 50,and positions the wafer mark within a detection area of mark detectionsystem MDS. That is, the full-shot one point measurement is performed,moving slider 10 within the XY plane with respect to mark detectionsystem MDS by a step-and-repeat method.

Note that in the case measurement unit 40 is equipped with a focalposition detection system, controller 60 _(i) may perform adjustment ofthe Z position of the wafer surface, based on detection results (output)of the focal position detection system, similarly to the description instep S106.

On alignment measurement (full-shot one point measurement) to all wafersin step S112, when slider 10 is moved within the XY plane, while anoffset load acts on surface plate 12 with the movement, in theembodiment, controller 60 _(i) individually performs feedforward controlon the three vibration isolators 14 so that the influence of the offsetload is canceled out according to the X, Y coordinate positions of theslider included in the measurement information on the first positionmeasurement system 30, and individually controls the drive force in theZ-axis direction that each of the vibration isolators 14 generates. Notethat controller 60 _(i) may individually perform feedforward control ofthe three vibration isolators 14 so that the influence of the offsetload is canceled out by predicting the offset load acting on surfaceplate 12 based on information on a known moving route of slider 10,without using the measurement information on the first positionmeasurement system 30. Also, in the embodiment, since information onunevenness (hereinafter called holder flatness information) of a waferholding surface (a surface set by the upper end of a plurality of pinsof a pin chuck) of wafer holder WH is to be obtained in advance byexperiment or the like, on alignment measurement (e.g., full-shot onepoint measurement), when slider 10 is moved, controller 60 _(i) finelyadjusts the Z position of surface plate 12 by performing feedforwardcontrol of the three vibration isolators 14 so that an area includingmeasurement target wafer marks on the wafer W surface is smoothlypositioned within a range of the focal depth of the optical system ofmark detection system MDS, based on the holder flatness information.Note that one of the feedforward control to cancel out the influence ofthe offset load acting on surface plate 12 and the feedforward controlbased on the holder flatness information described above, or both of thefeedforward controls do not have to be executed.

Note that in the case magnification of mark detection system MDS isadjustable, the magnification may be set low on search alignment, andthe magnification may be set high on alignment measurement. Also, in thecase center position displacement and residual rotation error of wafer Wloaded on slider 10 are small enough to be ignored, step S108 may beomitted.

In the full-shot one point measurement in step S112, actual measurementvalues are to be detected of position coordinates of the sample shotareas (sample shots) in the reference coordinate system used in the EGAoperation to be described later on. Sample shots, among all shots onwafer W, refer to specific shots of a plurality of numbers (at leastthree) decided in advance to be used in the EGA operation which will bedescribed later on. Note that in the full-shot one point measurement,all shots on wafer W are to be sample shots. After step S112, theprocessing proceeds to step S114.

In step S114, EGA operation is performed using position information onwafer marks measured in step S112. EGA operation, refers to astatistical calculation performed after measurement (EGA measurement) ofwafer marks described above for obtaining a coefficient of a modelformula which expresses a relation between a position coordinate of ashot and a correction amount of the position coordinate of the shotusing a statistical calculation such a least squares method, based ondata on a difference between a design value and the actual measurementvalue of a position coordinate of a sample shot.

In the embodiment, as an example, the following model formula is used tocalculate the correction amount from the design value of the positioncoordinate of the shot.

$\begin{matrix}\left. \begin{matrix}{{dx} = {a_{0} + {a_{1} \cdot X} + {a_{2} \cdot Y} + {a_{3} \cdot X^{2}} + {a_{4} \cdot X \cdot Y} + {a_{5} \cdot Y^{2}} +}} \\{{a_{6} \cdot X^{3}} + {{a_{7} \cdot X^{2}}Y} + {a_{8} \cdot X \cdot Y^{2}} + {{a_{9} \cdot Y^{3}}\mspace{14mu} \cdots}} \\{{dy} = {b_{0} + {b_{1} \cdot X} + {b_{2} \cdot Y} + {b_{3} \cdot X^{2}} + {b_{4} \cdot X \cdot Y} + {b_{5} \cdot Y^{2}} +}} \\{{b_{6} \cdot X^{3}} + {b_{7} \cdot X^{2} \cdot Y} + {b_{8} \cdot X \cdot Y^{2}} + {{b_{9} \cdot Y^{3}}\mspace{14mu} \cdots}}\end{matrix} \right\} & (1)\end{matrix}$

Here, dx and dy are correction amounts in the X-axis direction and theY-axis direction from design values of position coordinates of a shot,and X and Y are design position coordinates of the shot in a wafercoordinate system whose origin is set at the center of wafer W. That is,formula (1) described above is a polynomial expression of designposition coordinates X and Y of each shot in the wafer coordinate systemwhose origin is the center of the wafer, and is a model formula thatexpresses a relation between position coordinates X and Y and thecorrection amounts (alignment correction component) dx and dy of theposition coordinates of the shot. Note that in the embodiment, sincerotation between the reference coordinate system and the wafercoordinate system is canceled by the search alignment described earlier,the description below will be made describing the coordinate systems asthe reference coordinate system, without making any distinction inparticular between the reference coordinate system and the wafercoordinate system.

When using model formula (1), correction amount of the positioncoordinates of a shot can be obtained from coordinate positions X and Yof the shot of wafer W. However, to calculate this correction amount,coefficients a₀, a₁, . . . , b₀, b₁, . . . have to be obtained. AfterEGA measurement, coefficients a₀, a₁, . . . , b₀, b₁, . . . of formula(1) described above are obtained using statistical calculation such asthe least squares method, based on data on a difference between thedesign value and the actual measurement value of the position coordinateof the sample shot.

After coefficients a₀, a₁, . . . , b₀, b₁, . . . of formula (1) aredecided, by substituting design position coordinates X and Y of eachshot (divided area) in the wafer coordinate system into model formula(1) whose coefficients have been decided, and obtaining correctionamounts dx and dy of the position coordinates of each shot, a truearrangement (not only linear components but also including nonlinearcomponents as deformation components) can be obtained for the pluralityof shots (divided areas) on wafer W.

Now, in the case of wafer W on which exposure has already beenperformed, the waveform of detection signals obtained from themeasurement results is not always favorable for all wafer marks due tothe influence of the process so far. When positions of wafer markshaving such unfavorable measurement results (waveform of detectionsignals) are included in the EGA operation described above, positionerror of the wafer marks having such unfavorable measurement results(waveform of detection signals) has an adverse effect on the calculationresults of coefficients a₀, a₁, . . . , b₀, b₁, . . . .

Therefore, in the embodiment, signal processor 49 is to send onlymeasurement results of the wafer marks with favorable measurementresults to controller 60 _(i), and controller 60 _(i) is to execute theEGA operation described above, using positions of all the wafer markswhose measurement results have been received. Note that orders of thepolynomial expression in formula (1) described above are not limited inparticular. Controller 60 _(i) associates the results of EGA operationwith identification information (e.g., wafer number, lot number) of thewafers and stores the results as an alignment history data file in aninner or outer storage device. Note that information other than theresults of the EGA operation (e.g., information on marks used in the EGAoperation) may also be included in the alignment history data file.

When the EGA operation is finished in step S114, the processing proceedsto step S116 where wafer W is unloaded from slider 10. This unloading isperformed by wafer carrying system 70 _(i) and the vertical movementmember on slider 10 under the control of controller 60 _(i), in aprocedure opposite to the loading procedure in step S104. Note that inthe case each of a predetermined number of wafers that measurementdevice 100 _(i) is in charge of, the wafers being a part of the samelot, is sequentially carried into measurement device 100 _(i) and issequentially carried out from measurement device 100 _(i) concurrentlywith the measurement processing by measurement device 100 _(i), wafer Wwhich has finished measurement is delivered to carrying member 526 bywafer carrying system 70 _(i), carried to the unloading side waferdelivery position described earlier by carrying member 526, and then isto be returned into the predetermined FOPU 520 by robot 516.

In the next step S118, after count value i of the counter is incrementedby 1 (i←i+1), the processing proceeds to step S120 in which the judgmentis made of whether or not count value i is larger than a number M of thewafers that measurement device 100 _(i) is in charge of in the same lot.The number M is 9 in measurement device 100 ₁, and 8 in measurementdevices 100 ₂ and 100 ₃.

Then, in the case the judgment in this step S120 is negative, thejudgment is made that processing to all the wafers that measurementdevice 100 _(i) is in charge of is not yet complete, therefore, theprocessing returns to step S104, and thereinafter the processing fromstep S104 to step S120 (including making judgment) is repeated until thejudgment in step S120 is affirmed.

Then, when the judgment in step S120 is affirmed, this completes theseries of processing in this routine, according to the judgment that theprocessing to all the wafers that measurement device 100 _(i) is incharge of has been completed.

As is obvious from the description so far, according to measurementdevice 100 _(i), position information (coordinate position information)of at least one each of the wafer marks is measured for each of I (e.g.,98) shots on wafer W upon alignment measurement, and by using themeasured position information (excluding position information on wafermarks having unfavorable measurement results) in statistical calculationsuch as the least squares method, coefficients a₀, a₁, . . . , b₀, b₁, .. . of formula (1) above are obtained. Accordingly, it becomes possibleto accurately obtain deformation components of a wafer grid not only forlinear components but also for nonlinear components. Here, the wafergrid refers to a grid which is formed when the center of shots on waferW arranged according to a shot map (data concerning an arrangement ofshots formed on wafer W) are connected. Obtaining correction amounts(alignment correction components) dx and dy of position coordinates ofthe shots for a plurality of shots is none other than obtainingdeformation components of the wafer grid. Note that in the description,the wafer grid will be referred to shortly as a “grid,” or also as an“arrangement of shot area (or shot).”

In measurement system 500 ₁, measurement processing in accordance withthe flowchart described earlier can be performed concurrently by thethree measurement devices 100 ₁ to 100 ₃. That is, by measurementdevices 100 ₁ to 100 ₃, position measurement of at least one wafer markwith respect to all shots of each wafer can be performed on each of apredetermined number of wafers subject to measurement each housed insidethe wafer carrier; a total of one lot of wafers, within a measurementprocessing time required for substantially one third of the pieces ofwafers in one lot, and it becomes possible to accurately obtaindeformation components of the wafer grid not only for linear componentsbut also for nonlinear components. Note that also in the case ofperforming carry-in of the wafer to each measurement device 100 _(i) andcarry-out of the wafer that has been measured from each measurementdevice 100 ₁ concurrently with the measurement processing, processingcan be performed concurrently on the wafers in one lot inside FOUP 520carried into one loading port 514, and to the one lot of wafers,position measurement of at least one wafer mark with respect to allshots of each wafer becomes possible in a measurement processing time ofsubstantially one-third of the wafers in one lot, and it becomespossible to accurately obtain deformation components of the wafer gridnot only for linear components but also for nonlinear components. Notethat the three measurement devices 100 ₁ to 100 ₃ may be adjusted, forexample, using a reference wafer or the like, so that in the case eachof the three measurement devices 100 ₁ to 100 ₃ performs measurementprocessing on, for example, one wafer in one lot under the sameconditions, measurement results which are substantially the same can beobtained.

Information on the wafer grid of each wafer that has been obtained,e.g., data on deformation components of the wafer grid of each waferthat has been obtained (data of model formula (1) after coefficients a₀,a₁, . . . b₀, b₁, . . . have been determined) is sent to measurementsystem controller 530 ₁ as a part of alignment history data file foreach wafer by controller 60 _(i) of measurement device 100 _(i).Measurement system controller 530 ₁ stores the information on the wafergrid of each wafer that has been received, such as an alignment historydata file including data on deformation components of the wafer grid ofeach wafer that has been received (data of model formula (1) aftercoefficients a₀, a₁, . . . b₀, b₁, . . . have been determined), forexample, in an internal storage device for each wafer.

As is described above, in measurement devices 100 ₁ to 100 ₃, sincewafer measurement processing is performed on the 25 pieces of wafersincluded in one lot, concurrently dividing the processing into nine,eight, and eight pieces of wafers, the measurement processing bymeasurement devices 100 ₁ to 100 ₃ is completed almost simultaneously.Accordingly, measurement processing is completed in one-third of thetime required when compared to the case when the 25 pieces of wafers inthe same lot is sequentially processed using one measurement device.Note that in the case described above, processing is preferably startedwith measurement device 100 ₁ whose number of wafers in charge is onemore than that of the other devices.

Measurement system controller 530 ₁ sends information on the wafer grid(alignment history data file) for each of a plurality of wafers includedin one lot to host computer 2000, when measurement of all the wafersincluded in the lot has been completed. Needless to say, the informationon the wafer grid (alignment history data file) sent from measurementsystem 500 ₁ also includes data on nonlinear components of the wafergrid.

Note that controller 60 _(i) of measurement device 100 _(i) may beconnected to host computer 2000 via LAN 1500, and the information on thewafer grid (alignment history data file) may be sent from controller 60_(i) to host computer 2000, without going through measurement systemcontroller 530 ₁.

Also, in the embodiment, while the information on the wafer grid is tobe sent (output) from measurement system 500 ₁, the information (data)sent from measurement system 500 ₁ is not limited to this, and forexample, coordinate position information on a plurality of wafer marksmeasured by measurement device 100 _(i) may be sent (output) as a partof the alignment history data file for each wafer.

Note that of the 25 pieces of wafers included in one lot, in the casethe pieces of wafers that each of the measurement devices is in chargeare housed within a wafer carrier inside chamber 101 _(i) of measurementdevice 100 _(i), at the point when measurement is completed, the piecesof wafers that each of the measurement devices is in charge are returnedinto each of the wafer carriers. Therefore, in measurement systemcontroller 530 ₁, the wafers inside each of the wafer carriers have tobe returned into FOUP 520, using carrying system 521. Meanwhile, in thecase each of the wafers in one lot is to be sequentially carried intomeasurement devices 100 _(i) concurrently with the measurementprocessing of the three measurement devices 100 _(i), carrying member526 receives the wafer that has completed measurement from wafercarrying system 70 _(i) (i=one of 1 to 3), carries the wafer to theunloading side wafer delivery position described earlier, and robot 516carries (returns) the wafer on which processing has been performed andis carried to the unloading side wafer delivery position into FOUP 520.

Next, an operation flow will be described of a case in which processingis continuously performed on multiple wafers by the lithography systemincluding exposure apparatus 200 and C/D 300.

Firstly, the C/D inner carrying system (e.g., a SCARA robot) takes out afirst wafer (described as W₁) from a wafer carrier placed within achamber of C/D 300 and carries in the wafer to the coating section. Inaccordance with the carry-in, the coating section begins coating ofresist. When the coating of resist is completed, the C/D inner carryingsystem takes out wafer W₁ from the coating section, and carries thewafer into the baking section. In accordance with the carry-in, heatingprocessing (PB) of wafer W₁ begins at the baking section. Then, when PBof the wafer is completed, the C/D inner carrying system takes out waferW₁ from the baking section, and carries the wafer into temperaturecontrolling section 330. In accordance with the carry-in, cooling ofwafer W₁ using the cool plate inside temperature controlling section 330begins. This cooling is performed with the target temperature being atemperature which does not have any influence inside exposure apparatus200, generally, the target temperature of an air conditioning system ofexposure apparatus 200 which is decided, for example, in a range of 20to 25 degrees. Normally, at the point when the wafer is delivered totemperature controlling section 330, the temperature of the wafer iswithin a range of ±0.3 [° C.], however, temperature controlling section330 adjusts the temperature to a range of ±10 [mK] to the targettemperature.

Then, when the cooling (temperature control) inside temperaturecontrolling section 330 is completed, wafer W_(i) is mounted on aloading side substrate mounting section of a substrate delivery sectionprovided in between C/D 300 and exposure apparatus 200 by the C/D innercarrying system.

Inside C/D 300, a series of operations on wafers similar to the onesdescribed above as in resist coating, PB, cooling, and carryingoperation of the wafers described above that accompanies the series ofoperations are repeatedly performed, and the wafers are sequentiallymounted on the loading side substrate mounting section. Note thatpractically by providing two or more each of the coating section and theC/D inner carrying system inside the chamber of C/D 300, parallelprocessing on a plurality of wafers becomes possible and the timerequired for pre-exposure processing can be shortened.

Wafer W₁ mounted on the loading side substrate mounting sectiondescribed earlier is carried to a predetermined waiting position insideexposure apparatus 200 by wafer carrying system 270. However, the firstwafer, wafer W₁, is loaded immediately onto wafer stage WST by exposurecontroller 220, without waiting at the waiting position. This loading ofthe wafer is performed under the control of exposure controller 220similarly to the loading performed in measurement device 100 _(i)described earlier, using the vertical movement member (not shown) onwafer stage WST and wafer carrying system 270. After the loading, searchalignment similarly to the one described earlier and wafer alignment ofthe EGA method where shots of, e.g., around 3 to 16 are to be alignmentshots are performed to the wafer on wafer stage WST, using alignmentdetection system AS. On wafer alignment by the EGA method, alignmenthistory data file of the wafer (target wafer) subject to wafer alignmentand exposure in exposure apparatus 200 is supplied from host computer2000 to exposure controller 220 of exposure apparatus 200, along withidentification information (e.g., wafer number, lot number) and the likeof the target wafer. The alignment history data that exposure apparatus200 has acquired from host computer 2000 includes wafer grid informationon each wafer measured by measurement system 500 ₁, and exposurecontroller 220 performs wafer alignment as in the description below,after a predetermined preparatory operation. Note that exposurecontroller 220 and measurement system controller 530 ₁ may communicatealignment history data and the like, without going through host computer2000.

Here, the reason of performing wafer alignment of the EGA method whereshots of, e.g., around 3 to 16 are to be alignment shots in exposureapparatus 200 will be described, prior to specifically describing thewafer alignment.

Correction amounts (coefficients a₀, a₁, . . . , b₀, b₁, . . . offormula (1) described above) of position coordinates of shots on wafer Wobtained by measurement device 100 _(i) are used, for example, forpositioning of the wafer with respect to the exposure position onexposure of wafer W by exposure apparatus 200. However, wafer W whosecorrection amounts of position coordinates have been measured withmeasurement device 100 _(i) by exposure apparatus 200 is housed insideFOUP 520 after being unloaded from slider 10 of measurement device 100_(i) as is described earlier, and FOUP 520 is carried into C/D 300 bythe OHT and other carrying systems. Then, after wafer W is coated withresist by C/D 300, wafer W is loaded on wafer stage WST of exposureapparatus 200 for exposure. In this case, with wafer holder WH on slider10 and the wafer holder on wafer stage WST of exposure apparatus 200,holding state of wafer W differs due to individual difference betweenthe wafer holders even if the same type of wafer holder is used.Therefore, even if shot of wafer W position coordinates correctionamounts (coefficients a₀, a₁, . . . , b₀, b₁, . . . of formula (1)described above) of position coordinates of shots on wafer W areobtained with measurement device 100 _(i), all the coefficients a₀, a₁,. . . , b₀, b₁, . . . cannot be used as it is. However, it can beconsidered that low-order components (linear components) of thefirst-order or less of the correction amounts of the positioncoordinates of the shots are affected by the different holding state ofwafer W for each wafer holder, and high-order components of thesecond-order or more are hardly affected. This is because high-ordercomponents of the second-order or more are considered to be componentsthat occur due to deformation of wafer W induced mainly by the process,and it is safe to consider that the components have no relation to theholding state of the wafer by the wafer holders.

Based on such consideration, coefficients a₃, a₄, . . . , a₉ . . . , andb₃, b₄, . . . , b₉, . . . of high-order components obtained taking acertain amount of time for wafer W by measurement device 100 _(i) can beused without any changes also as coefficients of high-order componentsof the correction amounts of the position coordinates of wafer W inexposure apparatus 200. Accordingly, on wafer stage WST of exposureapparatus 200, performing only a simple EGA measurement (e.g.,measurement of around 3 to 16 wafer marks) to obtain linear componentsof the correction amounts of the position coordinates of wafer W isenough.

In exposure apparatus 200, a number of wafer marks corresponding to thenumber of alignment shots are selected as detection targets from wafermarks included in the alignment history data whose position informationis measured (marks whose position information is used when calculatingthe correction amounts) by measurement device 100 _(i), and the wafermarks serving as the detection targets are detected using alignmentdetection system AS, and based on the detection results and the position(measurement information according to interferometer system 218) ofwafer stage WST at the time of detection, position information on eachwafer mark of the detection targets is obtained, and using the positioninformation, EGA operation is performed and each coefficient of thefollowing formula (2) is obtained.

$\begin{matrix}\left. \begin{matrix}{{dx} = {c_{0} + {c_{1} \cdot X} + {c_{2} \cdot Y}}} \\{{dy} = {d_{0} + {d_{1} \cdot X} + {d_{2} \cdot Y}}}\end{matrix} \right\} & (2)\end{matrix}$

Then, exposure controller 220 replaces coefficients (c₀, c₁, c₂, d₀, d₁,d₂) obtained here with coefficients (a₀, a₁, a₂, b₀, b₁, b₂) included inthe data of deformation components of the wafer grid of the targetwafer, and by using a polynomial expression on design positioncoordinates X and Y of each shot in a wafer coordinate system whoseorigin is the center of the wafer expressed by the following formula (3)which includes the coefficients after replacement, obtains correctionamounts (alignment correction components) dx and dy of the positioncoordinates of each shot, and decides target positions (hereinaftercalled positioning target position for convenience) for positioning eachshot to the exposure position (projection position of the reticlepattern) on exposure of each shot for correcting the wafer grid, basedon the correction amounts. Note that in the embodiment, while exposureis performed not by a static exposure method but by a scanning exposuremethod, the target positions are referred to as positioning targetposition for convenience.

$\begin{matrix}\left. \begin{matrix}{{dx} = {c_{0} + {c_{1} \cdot X} + {c_{2} \cdot Y} + {a_{3} \cdot X^{2}} + {a_{4} \cdot X \cdot Y} + {a_{5} \cdot Y^{2}} +}} \\{{a_{6} \cdot X^{3}} + {{a_{7} \cdot X^{2}}Y} + {a_{8} \cdot X \cdot Y^{2}} + {{a_{9} \cdot Y^{3}}\mspace{14mu} \cdots}} \\{{dy} = {d_{0} + {d_{1} \cdot X} + {d_{2} \cdot Y} + {b_{3} \cdot X^{2}} + {b_{4} \cdot X \cdot Y} + {b_{5} \cdot Y^{2}} +}} \\{{b_{6} \cdot X^{3}} + {b_{7} \cdot X^{2} \cdot Y} + {b_{8} \cdot X \cdot Y^{2}} + {{b_{9} \cdot Y^{3}}\mspace{14mu} \cdots}}\end{matrix} \right\} & (3)\end{matrix}$

Note that since rotation between the reference coordinate system (stagecoordinate system) and the wafer coordinate system is canceled by thesearch alignment also in exposure apparatus 200, distinction between thereference coordinate system and the wafer coordinate system does nothave to be made in particular.

Then, exposure controller 220 performs exposure by a step-and-scanmethod to each shot on wafer W₁, while performing position control ofwafer stage WST according to the positioning target position.

Then, before exposure to the wafer on wafer stage WST (in this case,wafer W₁) is completed, a second wafer W₂ is mounted on the loading sidesubstrate mounting section of the substrate delivery section by the C/Dinner carrying system, and is carried to the predetermined waitingposition inside exposure apparatus 200 where it is kept waiting at thewaiting position.

Then, when exposure of wafer W₁ is completed, wafer W₁ and wafer W₂ areexchanged on wafer stage WST, and wafer alignment and exposure similarto the description earlier is performed on wafer W₂ that has beenexchanged. Note that in the case carriage of wafer W₂ to the waitingposition is not completed by the time exposure to the wafer on the waferstage (in this case, wafer W₁) is completed, the wafer stage is to waitnear the waiting position while holding the wafer that has been exposed.

Concurrently with the wafer alignment to wafer W₂ that has beenexchanged described above, wafer W₁ that has been exposed is carried toan unloading side substrate mounting section of the substrate deliverysection by wafer carrying system 270.

In the manner described earlier, the wafer that has been exposed mountedon the unloading side substrate mounting section of the substratedelivery section by wafer carrying system 270 is carried into the bakingsection by the C/D inner carrying system, and PEB is performed by abaking apparatus inside the baking section. Inside the baking section, aplurality of wafers can be housed at the same time.

Meanwhile, the wafer that has completed PEB is taken out from the bakingsection by the C/D inner carrying system, and is carried into thedeveloping section, and developing is started by a developing apparatusinside the developing section.

Then, when development of the wafer is completed, the wafer is taken outfrom the developing section by the C/D inner carrying system, and iscarried into FOUP 520 used at the time of carry-in, or to apredetermined housing stage inside a wafer carrier different from FOUP520. Hereinafter, inside C/D 300, to the wafers from the second waferonward that have been exposed, PEB, development, and wafer carriage areto be repeatedly performed in a procedure similar to wafer W₁.

Note that in the description above, while a two-dimensional mark is usedas the wafer mark, there are cases when one-dimensional marks, e.g., anX mark consisting of a line-and-space pattern whose periodic directionis in the X-axis direction, and a Y mark consisting of a line-and-spacepattern whose periodic direction is in the Y-axis direction are used asthe wafer mark. In this case, measurement conditions on measurement ofthe mark by mark detection system MDS may be different between the Xmark and the Y mark. While such a state may occur by various factors, anexample is to be assumed of a situation in which for example, alignmentin the Y-axis direction is performed (as a reference) on an immediatelypreceding layer, and alignment in the X-axis direction is performed (asa reference) on a layer one layer before the immediately precedinglayer, as is disclosed in, for example, U.S. Pat. No. 5,532,091 and thelike when alignment needs to be performed extending over a plurality oflayers (multilayer) formed on the wafer to perform overlay exposure onthe next layer. More specifically, positioning in the Y-axis directionis to be performed on the pattern (mark) formed on the outermost layerof the pattern layers already formed on wafer W, and positioning in theX-axis direction is to be performed on the pattern (mark) formed on thelayer below the outermost layer. Accordingly, when observing the X markat the time of alignment, the X mark formed on the layer below theoutermost layer is to be observed from the upper surface of wafer W, viathe outermost layer on which the Y mark is formed. Therefore, thealignment measurement conditions (such as illumination conditions,optical conditions, and signal processing algorithms) for appropriatelymeasuring the X mark is different from the alignment measurementconditions for appropriately measuring the Y mark.

Next, a measurement method for measuring position information(coordinate position information) of the X mark and Y mark for each ofthe I (e.g., 98 shots) shots on the measurement wafer using twomeasurement devices of measurement system 500 ₁ will be described. FIG.12 schematically shows a flow of processing in the measurement method inthis case.

First of all, in step S202, a FOUP in which a plurality of wafers of acertain lot including wafer W₁₁ (measurement target substrate) ishoused, is mounted on loading port 514 of measurement system 500 ₁,using OHT and the like described above. The plurality of wafers of acertain lot including wafer W₁₁ housed in the FOUP is sequentially takenout from the FOUP using robot 516 and the like, and then is sequentiallycarried to at least one of measurement devices 100 _(i) (i=1 to 3),using carrying system 512 and the like.

Note that in the description below, while one wafer of the plurality ofwafers housed in the FOUP is described as wafer W₁₁, a similarprocessing is performed on all the plurality of wafers housed in theFOUP. Also, in the description below, as an example, a case will bedescribed for wafer W₁₁ in which measurement of the Y mark is performedusing measurement device 100 ₂, after performing measurement of the Xmark using measurement device 100 ₁. As a matter of course, measurementof the X mark may be performed using measurement device 100 ₂, afterperforming measurement of the Y mark using measurement device 100 ₁.

Wafer W₁₁, next in step S204, when carried to measurement device 100 ₁in the manner described above, is loaded onto slider 10 of measurementdevice 100 ₁ in a procedure similar to step S104 described earlier bywafer carrying system 70 ₁ and vertical movement member on slider 10,under the control of controller 60 ₁.

In the next step S206, measurement conditions of the X mark of wafer W₁₁by measurement device 100 ₁ is set as a first predetermined condition.In the description below, this first predetermined condition will alsobe referred to as a second condition to discriminate this from the firstcondition described earlier. The second condition is a measurementcondition suitable for detection of the X mark formed on wafer W₁₁.Here, as an alignment measurement condition (an example of the secondcondition), optimization of the wavelength of the illumination light inmark detection system MDS is to be performed, as is described earlier.The X mark formed on wafer W₁₁ subject to processing is a mark formed ona lower layer (e.g., one layer below) when the outermost layer serves asan upper layer, and to appropriately observe the mark, an observationlight (illumination light) is preferably used that has hightransmittance with respect to the material that structures the outermostlayer. Here, such an observation light is to be, e.g., light in the redregion. Therefore, controller 60 ₁ performs setting (control) of thewavelength selection mechanism, so that a filter that transmits a lightbeam (red light) having a wavelength of 710 to 800 nm in the wavelengthselection mechanism of mark detection system MDS is to be selected.

Next, in step S208, absolute position coordinates within the XY plane ofI X marks of wafer W₁₁ are obtained in the following manner, under thesecond condition which has been set. That is, controller 60 ₁ detectseach of the I X marks on wafer W₁₁ using mark detection system MDS,while measuring the position information on slider 10 using the firstposition measurement system 30 (and the second position measurementsystem 50), and obtains the absolute position coordinates in the XYplane of the I X marks on wafer W₁₁, based on detection results of eachof the I X marks and the absolute position coordinates (X, Y) of slider10 at the time of detection of each of the X marks. However, in thiscase, by irradiating the wafer mark with detection light of a wavelengthin the red region determined by the second condition, via the opticalsystem of mark detection system MDS, at a light amount of a defaultsetting in a conventional illumination condition (σ value), receiving adiffracted light of a predetermined order (e.g., ±1st order) generatedfrom the wafer mark by a detector, and processing the photo-electricallyconverted signal according to a signal processing condition (processingalgorithm) of a default setting, detection results of the mark used tocalculate position coordinates on a reference coordinate system of thewafer mark on wafer W₁₁ can be obtained. Also, on this operation,controller 60 ₁, based on measurement values in the θx direction and theθy direction of slider 10 measured by the first position measurementsystem 30, obtains the absolute position coordinates within the XY planeof each of the I X marks, with Abbe errors in the X-axis direction andthe Y-axis direction of the first position measurement system 30 and themeasurement values in the X-axis direction and the Y-axis direction ofthe second position measurement system 50 serving as offsets.

Next, in step S210, wafer W₁₁ is unloaded from slider 10 of measurementdevice 100 ₁ and is loaded onto slider 10 of measurement device 100 ₂,without being carried out outside of measurement system 500 ₁.Specifically, wafer W₁₁, after being unloaded from slider 10 ofmeasurement device 100 ₁ by wafer carrying system 70 ₁ and the verticalmovement member on slider 10 in a procedure opposite to the loadingprocedure in step S204 (and step 104) under the control of controller 60₁, is delivered to carrying member 524 (or 526) by wafer carrying system70 ₁, and then is carried to a delivery position with measurement device100 ₂ by carrying member 524 (or 526). Thereafter, under the control ofcontroller 60 ₂ in a procedure similar to step S104 described earlier,wafer W₁₁ is loaded onto slider 10 of measurement device 100 ₂ by wafercarrying system 70 ₂ and vertical movement member on slider 10 ofmeasurement device 100 ₂.

In the next step S212, measurement conditions of the Y mark of wafer W₁₁by measurement device 100 ₂ is set as a second predetermined condition.In the description below, this second predetermined condition will alsobe referred to as a third condition. The third condition is ameasurement condition suitable for detection of the Y mark formed onwafer W₁₁. Here, as an alignment measurement condition (an example ofthe third condition), optimization of the wavelength of the illuminationlight in mark detection system MDS is to be performed, as is describedearlier. The Y mark formed on wafer W₁₁ subject to processing is a markformed on the outermost layer, and to observe this, the wavelength of aspecific observation light (illumination light) does not have to bespecified, and a broadband white light generated by an illuminationlight source such as a halogen lamp may be used for observation.Accordingly, controller 60 ₅ performs setting (control) of thewavelength selection mechanism, so that a filter that transmits a lightbeam (white light) having a wavelength of 530 to 800 nm in thewavelength selection mechanism of mark detection system MDS is to beselected.

Next, in step S214, absolute position coordinates within the XY plane ofI Y marks of wafer W₁₁ are obtained similarly to obtaining the absoluteposition coordinates within the XY plane of the X marks in step S208,under the third condition which has been set by controller 60 ₂. On thisoperation, controller 60 ₂ obtains the absolute position coordinateswithin the XY plane of each of the I Y marks, with Abbe errors in theX-axis direction and the Y-axis direction of the first positionmeasurement system 30 obtained based on measurement values of slider 10in the θx direction and the θy direction measured by the first positionmeasurement system 30, and the measurement values in the X-axisdirection and the Y-axis direction of the second position measurementsystem 50, serving as offsets.

As is described above, the three measurement devices 100 ₁ to 100 ₃ areadjusted, so that in the case each of the three measurement devices 100₁ to 100 ₃ performs measurement processing on, for example, one wafer inone lot under the same conditions, measurement results which aresubstantially the same can be obtained. Accordingly, in the next stepS216, by measurement system controller 530 ₁ (or controller 60 ₂),coefficients a₀, a₁, . . . , b₀, b₁, . . . in formula (1) above areobtained by a statistical calculation (EGA operation) such as the leastsquares method, based on the absolute position coordinates of the X markobtained in step S208 and the absolute position coordinates of the Ymark obtained in step S214, similarly to step S114 described above.Hereinafter, similarly to the flowchart in FIG. 11, when the measurementprocessing to the wafers in the lot subject to measurement is completed,this completes the series of processing.

As is described, in this example, measurement of the X marks isperformed on all wafers in the lot under the second condition inmeasurement device 100 ₁, and measurement of the Y marks can beperformed on all wafers in the lot under the third condition inmeasurement device 100 ₂. Accordingly, measurement device 100 ₁ andmeasurement device 100 ₂ can accurately measure each of the measurementtarget marks without changing each of the measurement conditions, untilmeasurement on all wafers in the lot subject to measurement iscompleted.

Measurement system controller 530 ₁ sends information on the wafer grid(alignment history data file) for each of a plurality of wafers includedin one lot to host computer 2000, when measurement of all the wafersincluded in the lot has been completed. Needless to say, the informationon the wafer grid (alignment history data file) sent from measurementsystem 500 ₁ also includes data on nonlinear components of the wafergrid.

Note that controller 60 _(i) of measurement device 100 _(i) may beconnected to host computer 2000 via LAN 1500, and the information on thewafer grid (alignment history data file) may be sent from controller 60_(i) to host computer 2000, without going through measurement systemcontroller 530 ₁.

Also, in the embodiment, while information on the wafer grid is sent(output) from measurement system 500 ₁, the information (data) sent frommeasurement system 500 ₁ is not limited to this, and for example,coordinate position information on the wafer mark (X mark) andcoordinate position information on the wafer mark (Y mark) measured bymeasurement device 100 ₁ may be sent (output) as at least a part ofalignment history data of each wafer.

Note that in measurement system 500 ₁, it is possible to concurrentlyperform at least a part of acquiring the absolute position coordinate ofthe X mark of a wafer included in a measurement target lot bymeasurement device 100 ₁ and acquiring the absolute position coordinateof the Y mark of another wafer included in the measurement target lot bymeasurement device 100 ₂. In such a case, it becomes possible to reducemeasurement time of all wafers that are measurement targets included inthe measurement target lot.

Also, in the description above, while a wafer on which the X mark andthe Y mark are formed on different layers serves as the measurementtarget, the X mark and the Y mark may be formed on the same layer. Inthis case as well, in the case the measurement condition suitable fordetection of the X mark and the measurement condition suitable for the Ymark are different, for example, the absolute position coordinate of theX mark may be acquired by measurement device 100 ₁ and the absoluteposition coordinate of the Y mark may be acquired by measurement device100 ₂.

Now, as is described above, since measurement device 100 _(i) isequipped with the first position measurement system 30, by performingorigin setting of the orthogonal coordinate system (reference coordinatesystem) set by the measurement axes of the first position measurementsystem 30, it becomes possible to manage an absolute position of slider10, and as a consequence, an absolute position of the wafer marks, suchas overlay measurement marks (registration marks) on wafer W held onslider 10 obtained from the position information on slider 10 and thedetection results of mark detection system MDS, on the referencecoordinate system. That is, measurement device 100 _(i) can also be madeto function as overlay measuring instrument. Note that in thedescription, “absolute position” refers to coordinate positions on areference coordinate system.

Accordingly, at least one of measurement devices 100 _(i) (i=1 to 3) ofmeasurement system 500 ₁ can also be made to function as an overlaymeasuring instrument. However, in the embodiment, since each of themeasurement devices 100 _(i) of measurement system 500 ₁ is to performthe measurement described earlier on a wafer that has finished theprocessing of the pre-process in the wafer processing described earlierand has not yet been coated with a resist as a measurement target,concurrently with this measurement on a wafer in a certain lot by eachmeasurement device 100 _(i) of measurement system 500 ₁, it is possibleto execute overlay measurement and the like to a wafer in another lotwith measurement system 500 ₂.

Next, an overlay measurement method will be described, using twomeasurement devices of the other measurement system 500 ₂. FIGS. 13 and14 schematically show a flow of processing in the overlay measurementmethod in this case.

First of all, in step S302, a wafer (expressed as wafer W₁₁) included ina certain lot is carried into C/D 300, and in the coating section of C/D300, by exposure apparatus 200 or an exposure apparatus different fromexposure apparatus 200 such as for example, a scanner or a stepper,resist coating is performed on wafer W₁₁ which has undergone exposure ofthe first layer (lower layer). On wafer W₁₁ before resist coating, byexposure of the lower layer, along with a plurality of, for example, I(I is, for example, 98) shots, a wafer mark whose designed positionalrelation with the shot is known and a first mark (to be precise, aresist image of the first mark (also appropriately referred to as afirst mark image)) for overlay displacement measurement are formed,corresponding to each of the shots. In this case, designed positionalrelation is also known for each of the I first mark images.

Next, in step S304, wafer W₁₁ that has been coated with the resist isloaded onto wafer stage WST of exposure apparatus 200, after goingthrough a predetermined processing process similar to wafer W_(i)described earlier. Specifically, wafer W₁₁ is loaded onto wafer stageWST, after having undergone heating processing (PB) in the bakingsection, temperature control in temperature controlling section 330 andthe like.

Next, in step S306, by exposure controller 220 of exposure apparatus200, to wafer W₁₁ on wafer stage WST, search alignment similar to theone described earlier using alignment detection system AS and waferalignment by the EGA method in which alignment shots are, e.g., around 3to 16 shots are performed.

Note that prior to step S302, as is described earlier, information onthe wafer grid of wafer W₁₁ is obtained by measurement device 100 _(i)(i=1 to 3) of measurement system 500 ₁, which is supplied to exposurecontroller 220 of exposure apparatus 200.

In the next step, step S308, exposure controller 220 obtains correctionamounts (alignment correction components) dx and dy of positioncoordinates of each shot expressed in formula (3) described earlierbased on results of the wafer alignment, and decides positioning targetposition on exposure of each shot for correcting the wafer grid, basedon the correction amounts.

Note that prior to step 302, positioning target position on exposure ofeach shot may be decided only by the results of wafer alignment by theEGA method using alignment detection system AS in which alignment shotsare, e.g., around 3 to 16 shots, without obtaining information on thewafer grid of wafer W₁₁ by measurement device 100 _(i) of measurementsystem 500 ₁.

Next, in step S310, exposure apparatus 200 performs exposure of a secondlayer (an upper layer whose lower layer is the first layer) by astep-and-scan method to each shot on wafer W₁₁, while controlling waferstage WST according to the positioning target position. On thisoperation, exposure apparatus 200 performs exposure using a reticle (tobe reticle R₁₁ for convenience) on which a second mark corresponding tothe first mark image on wafer W₁₁ is formed. Accordingly, by thisexposure of the second layer, the pattern area of reticle R₁₁ isoverlaid and transferred with respect to I shots on wafer W₁₁, alongwith transferred images of I second marks being formed arranged in apositional relation corresponding to the positional relation of the Ifirst marks.

Next, in step S312, wafer W₁₁ that has completed exposure of the secondlayer is carried into the developing section of C/D 300, after goingthrough a processing process similar to wafer W₁ described earlier thathas already been exposed. Specifically, wafer W₁₁ is carried to theunloading side substrate mounting section of the substrate deliverysection by wafer carrying system 270, and is carried into the bakingsection of C/D 300 from the unloading side substrate mounting section bythe C/D inner carrying system, and then PEB is performed by a bakingapparatus inside the baking section. Wafer W₁₁ that has completed PEB istaken out from the baking section by the C/D inner carrying system, andthen is carried into the developing section.

Next, in step S314, by the developing apparatus within the developingsection, wafer W₁₁ on which a transferred image of a plurality of secondmarks is formed is developed. By this development, along with I shots, Isets of the first mark image and the corresponding second mark image areformed in predetermined positional relation on wafer W₁₁, which serve asa measurement target on overlay measurement. That is, the substrateserving as a measurement target on overlay measurement (overlaymeasurement target substrate) is made in this manner. Here, as a set ofthe first mark image and the corresponding second mark image, forexample, a resist image of a box-in-box mark consisting of an externalbox mark and an in-box mark arranged on the inner side of the externalbox can be used.

Next, in step S316, a FOUP in which a plurality of wafers of a certainlot including wafer W₁₁ (overlay measurement target substrate) that hasbeen developed is housed, is taken out from C/D 300, and is mounted onloading port 514 of measurement system 500 ₂, using OHT described aboveand the like. That is, a plurality of wafers of a certain lot includingwafer W₁₁ inside the FOUP taken out from C/D 300 is carried tomeasurement system 500 ₂ before the process processing (etchingprocessing, or film deposition processing after the etching processing(including at least one of sputtering processing, CVD processing, andthermal oxidation processing)) performed after development processing isapplied. The plurality of wafers of a certain lot including wafer W₁₁housed in the FOUP is sequentially taken out from the FOUP using robot516 and the like, and then is sequentially carried to at least one ofmeasurement devices 100 _(i) (i=4 to 6), using carrying system 521 andthe like.

Note that in the description below, while one wafer of the plurality ofwafers housed in the FOUP is described as wafer W₁₁, a similarprocessing is performed on all, or on a part of the plurality of wafershoused in the FOUP. Also, in the description below, as an example, acase will be described for wafer W₁₁ (measurement target substrate onoverlay measurement) in which measurement of the first mark image isperformed using measurement device 100 ₄, and measurement of the secondmark image is performed using measurement device 100 ₅.

Wafer W₁₁, next in step S318, when carried to measurement device 100 ₄in the manner described above, is loaded onto slider 10 of measurementdevice 100 ₄ in a procedure similar to step S104 described earlier bywafer carrying system 70 ₄ and vertical movement member on slider 10,under the control of controller 60 ₄.

In the next step S320, measurement conditions of the first mark image ofwafer W₁₁ by measurement device 100 ₄ is set as a first predeterminedcondition. In the description below, this first predetermined conditionwill also be referred to as a second condition to discriminate this fromthe first condition described earlier. The second condition is ameasurement condition suitable for detection of the first mark imageformed on wafer W₁₁ by exposure of the first layer. Here, as analignment measurement condition (an example of the second condition),optimization of the wavelength of the illumination light in markdetection system MDS is to be performed, as is described earlier. Thefirst mark image formed on wafer W₁₁ subject to processing is a markformed on a first layer (a lower layer (e.g., one layer below) when asecond layer (outermost layer) serves as an upper layer), and toappropriately observe the mark, an observation light (illuminationlight) is preferably used that has high transmittance with respect tothe material that structures the outermost layer. Here, such anobservation light is to be, e.g., light in the red region. Therefore,controller 604 performs setting (control) of the wavelength selectionmechanism, so that a filter that transmits a light beam (red light)having a wavelength of 710 to 800 nm in the wavelength selectionmechanism of mark detection system MDS is to be selected.

Next, in step S322, absolute position coordinates within the XY plane ofI first mark images of wafer W₁₁ are obtained in the following manner,under the second condition which has been set. That is, controller 60 ₄detects each of the I first mark images on wafer W₁₁ using markdetection system MDS, while measuring the position information on slider10 using the first position measurement system 30 (and the secondposition measurement system 50), and obtains the absolute positioncoordinates in the XY plane of the I first mark images on wafer W₁₁,based on detection results of each of the I first mark images and theabsolute position coordinates (X, Y) of slider 10 at the time ofdetection for each of the first mark images. However, in this case, byirradiating the wafer mark with detection light of a wavelength in thered region determined by the second condition, via the optical system ofmark detection system MDS, at a light amount of a default setting in aconventional illumination condition (σ value), receiving a diffractedlight of a predetermined order (e.g., ±1st order) generated from thewafer mark by a detector, and processing the photo-electricallyconverted signal according to a signal processing condition (processingalgorithm) of a default setting, detection results of the mark used tocalculate position coordinates on a reference coordinate system of thewafer mark on wafer W₁₁ can be obtained. Also, on this operation,controller 60 ₄, based on measurement values in the ex direction and theθy direction of slider 10 measured by the first position measurementsystem 30, obtains the absolute position coordinates within the XY planeof each of the I first mark images, with Abbe errors in the X-axisdirection and the Y-axis direction of the first position measurementsystem 30 and the measurement values in the X-axis direction and theY-axis direction of the second position measurement system 50 serving asoffsets.

Next, in step S324, wafer W₁₁ is unloaded from slider 10 of measurementdevice 100 ₄ and is loaded onto slider 10 of measurement device 100 ₃,without being carried out outside of measurement system 500 ₂.Specifically, wafer W₁₁, after being unloaded from slider 10 ofmeasurement device 100 ₄ by wafer carrying system 70 ₄ and the verticalmovement member on slider 10 in a procedure opposite to the loadingprocedure in step S318 (and step 104) under the control of controller 60₄, is delivered to carrying member 524 (or 526) by wafer carrying system70 ₄, and then is carried to a delivery position with measurement device100 ₅ by carrying member 524 (or 526). Thereafter, under the control ofcontroller 60 ₅ in a procedure similar to step S104 described earlier,wafer W₁₁ is loaded onto slider 10 of measurement device 100 ₅ by wafercarrying system 70 ₅ and vertical movement member on slider 10 ofmeasurement device 100 ₅.

In the next step S326, measurement conditions of the second mark imageof wafer W₁₁ by measurement device 100 ₅ is set as a secondpredetermined condition. In the description below, this secondpredetermined condition will also be referred to as a third condition.The third condition is a measurement condition suitable for detection ofthe second mark image formed on wafer W₁₁ by exposure of the secondlayer. Here, as an alignment measurement condition (an example of thethird condition), optimization of the wavelength of the illuminationlight in mark detection system MDS is to be performed, as is describedearlier. The second mark image formed on wafer W₁₁ subject to processingis a mark formed on the second layer (the outermost layer), and toobserve this, the wavelength of a specific observation light(illumination light) does not have to be specified, and a broadbandwhite light generated by an illumination light source such as a halogenlamp may be used for observation. Accordingly, controller 60 ₅ performssetting (control) of the wavelength selection mechanism, so that afilter that transmits a light beam (white light) having a wavelength of530 to 800 nm in the wavelength selection mechanism of mark detectionsystem MDS is to be selected.

Next, in step S328, absolute position coordinates within the XY plane ofI second mark images of wafer W₁₁ are obtained similarly to obtainingthe absolute position coordinates within the XY plane of the first markimages in step S322, under the third condition which has been set bycontroller 60 ₅. On this operation, controller 60 ₃, based onmeasurement values in the θx direction and the θy direction of slider 10measured by the first position measurement system 30, obtains theabsolute position coordinates within the XY plane of each of the Isecond mark images, with Abbe errors in the X-axis direction and theY-axis direction of the first position measurement system 30 and themeasurement values in the X-axis direction and the Y-axis direction ofthe second position measurement system 50 serving as offsets.

Next, in step S330, by measurement system controller 530 ₂ (orcontroller 60 ₅), overlay error (overlay displacement) between the firstlayer and the second layer is obtained, based on the absolute positioncoordinates of the first mark image and the absolute positioncoordinates of the second mark image that make a set with each other.

Next, in step 332, by measurement system controller 530 ₂ (or controller60 ₅), a judgment is made, for example, in the following manner onwhether exposure of the first layer or exposure of the second layer isthe main cause of the overlay error, based on the absolute positioncoordinates of I first mark images and the absolute position coordinatesof I second mark images. That is, measurement system controller 530 ₂(or controller 60 ₅) obtains displacement amount (ΔX1₁, ΔY1₁) (i=1 to I)from design position coordinates of the first mark image anddisplacement amount (ΔX2₁, ΔY2₁) (i=1 to I) from design positioncoordinates of the second mark image, and for each of ΔX1₁, ΔX2₁,ΔY1_(i), and ΔY2₁, obtains the sum total of i=1 to I, ΣX1_(i), ΣX2_(i),ΣY1_(i), and ΣY2_(i). Then, in the case of ΣX1_(i)>ΣX2_(i) andΣY1_(i)>ΣY2_(i), measurement system controller 530 ₂ (or controller 60₅) judges that the overlay error is mainly caused by exposure of thefirst layer for both the X-axis direction and the Y-axis direction, andin the case of ΣX1_(i)<ΣX2_(i) and ΣY1_(i)<ΣY2 _(i), measurement systemcontroller 530 ₂ (or controller 60 ₅) judges that the overlay error ismainly caused by exposure of the second layer for both the X-axisdirection and the Y-axis direction. Also, in the case of ΣX1_(i)>ΣX2_(i)and ΣY1_(i)<ΣY2_(i), measurement system controller 530 ₂ (or controller60 ₅) judges that the overlay error is mainly caused by exposure of thefirst layer in the X-axis direction and exposure of the second layer inthe Y-axis direction, and in the case of ΣX1_(i)<ΣX2_(i) andΣY1_(i)>ΣY2_(i), controller 530 ₂ (or controller 60 ₅) judges that theoverlay error is mainly caused by exposure of the second layer in theX-axis direction and exposure of the first layer in the Y-axisdirection.

Note that the deciding method described above is an example, and as longas measurement system controller 530 ₂ (or controller 60 ₅) makes thejudgment of whether the main cause of the overlay error is in exposureof the first layer or exposure of the second layer, based on theabsolute position coordinates of the I first mark images and theabsolute position coordinates of the I second mark images, the specificjudgment method does not matter.

Note that concurrently with the processing in step S330 and step S332,wafer W₁₁ on which measurement has been completed of the absoluteposition coordinate within the XY plane of I second mark images in stepS328 is delivered to carrying member 526 by wafer carrying system 70 ₅,and after being carried to the unloading side wafer delivery positiondescribed earlier by carrying member 526, is to be returned into thepredetermined FOPU 520 by robot 516.

Data on the overlay error (overlay displacement) of wafer W₁₁ obtainedby the overlay measurement method described above and data on judgmentresults of whether the main cause of the overlay error is in exposure ofthe first layer or exposure of the second layer are to be fed back to atleast one of the exposure apparatus that performed the exposure of thefirst layer and exposure apparatus 200 that performed exposure of thesecond layer by measurement system controller 530 ₂ (or controller 60₅).

For example, in the case the main factor of the overlay error is inexposure of the first layer, the data can be fed back to the exposureapparatus that has performed exposure on the first layer. Then, in thecase the exposure apparatus performs an exposure processing similar tothat of the first layer of wafer W₁₁ on a wafer included in a lot otherthan the lot including wafer W₁₁, a positioning target position may bedecided so that the overlay error with the second layer is reduced,based on the data fed back.

Also, in the case the main factor of overlay error is in exposure of thesecond layer, the data may be fed back to exposure apparatus 200 thathas performed exposure on the second layer. Then, in the case exposureapparatus 200 performs an exposure processing similar to that of thesecond layer of wafer W₁₁ on a wafer included in a lot other than thelot including wafer W₁₁, a positioning target position may be decided sothat the overlay error with the first layer is reduced, based on thedata fed back.

Note that feedback of data may be performed, via host computer 2000.

Also, in at least one of step S322 and step S328, in the case theabsolute position coordinates for two or more marks are acquired for allshots on wafer W₁₁, and first information related to shape and size ofeach shot on the first layer and second information related to shape andsize of each shot on the second layer can be acquired, the firstinformation may be supplied (fed back) to the exposure apparatus thathas performed exposure on the first layer and the second information maybe supplied (fed back) to exposure apparatus 200 that has performedexposure on the second layer. In this case, image forming characteristiccorrection controller 248 may be controlled, or at least one of speedand direction of reticle stage RST may be controlled, so that the shapeand size of each shot on the second layer take the form of a desiredstate.

Note that in the description above, while the overlay error (overlaydisplacement) between the first layer and the second layer is obtainedbased on the absolute position coordinates of the first mark image andthe absolute position coordinates of the second mark image, data on theabsolute position coordinates of the first mark image and data on theabsolute position coordinates of the second mark image may be outputfrom measurement system 500 ₂ as information on overlay error betweenthe first layer and the second layer (position displacement between thefirst layer and the second layer). In this case, data output frommeasurement system 500 ₂ may be supplied (fed back) to one of theexposure apparatus (exposure apparatus 200 or another exposureapparatus) that has performed exposure on the first layer and exposureapparatus 200 that has performed exposure on the second layer.

Also, each of the position displacement between the first mark image andthe second mark image that form a set with each other may be obtainedbased on the absolute position coordinates of the first mark image andthe absolute position coordinates of the second mark image, and thepositional displacement may be output from measurement system 500 ₂ asinformation on overlay error between the first layer and the secondlayer (position displacement between the first layer and the secondlayer). Also in this case, data output from measurement system 500 ₂ maybe supplied (fed back) to one of the exposure apparatus (exposureapparatus 200 or another exposure apparatus) that has performed exposureon the first layer and exposure apparatus 200 that has performedexposure on the second layer.

Note that in the processing algorithm that follows the flowchart inFIGS. 13 and 14, in the case measurement of the absolute positioncoordinate of the first mark image is performed with measurement device100 ₄ in step S322 on all overlay measurement target substrates (waferW₁₁) included in the same lot, while measurement of the absoluteposition coordinate of the second mark image is to be performed withmeasurement device 100 ₅ in step S328 on the overlay measurement targetsubstrates, the measurement of the absolute position coordinate of thesecond mark image with measurement device 100 ₅ does not necessarilyhave to be performed on a part of the measurement target substrates inthe lot.

Note that the absolute position coordinates of K first mark images,which is less than I, may be obtained in step S322, and the absoluteposition coordinates of K second mark images may be obtained in stepS328.

As is obvious from the description above, with the overlay measurementmethod performed in substrate processing system 1000, measurement system500 ₂ can measure each of the absolute position coordinates of the firstmark image and the absolute position coordinates of the second markimage, and can measure overlay error based on these absolute positioncoordinates. Also, an unconventional significant effect can be obtainedin which the main cause of the overlay error can be specified toexposure of the lower layer or to exposure of the upper layer.

Note that since the overlay error (overlay displacement) between thefirst layer and the second layer is obtained in step S330 describedabove, step S332 may be executed as necessary.

Note that in the description above, while overlay displacementmeasurement marks (the first mark image and the second mark image) wereused to obtain the overlay error between the first layer and the secondlayer, wafer marks (alignment marks) may also be used. That is, theoverlay error between the first layer and the second layer may beobtained from the absolute position coordinates of I wafer marks of thefirst layer and the absolute position coordinates of I wafer marks ofthe second layer.

Also, since the wafer mark and the overlay displacement measurement mark(the first mark image and the second mark image) differ in shape, sizeand the like, suitable measurement conditions including illuminationcondition and the like differ. Therefore, for the plurality of wafersincluded in the same lot (measurement target lot), in step S320described earlier, a measurement condition suitable for measurement ofthe resist image of the wafer mark on the wafer is to be set as thefirst predetermined condition instead of the measurement condition ofthe first mark image of wafer W₁₁, and in step S322, the absoluteposition coordinates of the resist image of the wafer mark is to beobtained under the first predetermined condition. Also, as for the waferin which the absolute position coordinates of the resist image of thewafer mark is acquired, in step S326 described earlier, measurementconditions suitable for measurement of an overlay displacementmeasurement mark (at least one of the first mark image and the secondmark image) may be set as the second predetermined condition, and instep S328, the absolute position coordinates of the overlay displacementmeasurement mark may be obtained under the second predeterminedconditions. Therefore, it is possible to perform position measurementwith high precision for both the resist image of the wafer mark and theoverlay displacement measurement mark on the plurality of wafersincluded in the measurement target lot, in the flow of processingaccording to the flowchart in FIGS. 13 and 14.

Also, in the description above, after the exposure processing of thesecond layer, the absolute position coordinate of the first mark image(or the wafer mark of the first layer) of wafer W₁₁ that has beendeveloped is acquired by measurement device 100 ₄ of measurement system500 ₂, and the absolute position coordinate of the second mark image (orthe wafer mark of the second layer) is acquired by measurement device100 ₅. However, the acquisition is not limited to this, and the absoluteposition coordinate of the first mark image (or the wafer mark of thefirst layer) of wafer W₁₁ that has been developed may be acquired bymeasurement device 100 ₄ of measurement system 500 ₂ after the exposureprocessing of the first layer and before the exposure processing of thesecond layer, and the absolute position coordinate of the second markimage (or the wafer mark of the second layer) of wafer W₁₁ that has beendeveloped may be acquired by measurement device 100 ₅ of measurementsystem 500. In this case, the overlay error between the first layer andthe second layer may be obtained with measurement system 500 ₂(controller 60 ₅ or measurement system controller 530 ₂), or may beobtained with another device (e.g., host computer 2000).

Also, wafer W₁₁ may be carried into measurement system 500 ₁ ormeasurement system 500 ₂ just before wafer W₁₁ that has gone throughvarious processes (including etching processing and film depositionprocessing) is carried into C/D 300 (or another coater/developer) sothat exposure processing is performed on the following layer of thesecond layer, and any one of measurement devices 100 _(i) (i=one of 1 to6) may acquire both the absolute position coordinates of the first markimage (or wafer mark of the first layer) and the absolute positioncoordinates of the second mark image (or wafer mark of the second layer)of wafer or the absolute position coordinates of the second mark image(or wafer mark of the second layer) of wafer W₁₁. Also in this case, theoverlay error between the first layer and the second layer (positiondisplacement between the first layer and the second layer) may beobtained by measurement system 500 ₁ or measurement system 500 ₂, orinformation on the absolute position coordinates acquired by measurementsystem 500 ₁ or measurement system 500 ₂ may be supplied to anotherapparatus (e.g., host computer 2000), and the another apparatus mayobtain the overlay error between the first layer and the second layer(position displacement between the first layer and the second layer).Also, information on the overlay error between the first layer and thesecond layer (position displacement between the first layer and thesecond layer) obtained by measurement system 500 ₁ or measurement system500 ₂, or information on the absolute position coordinates acquired bymeasurement system 500 ₁ or measurement system 500 ₂ may be supplied toexposure apparatus 200, or to another exposure apparatus.

Note that in the description above, while information on the overlayerror between the first layer and the second layer is acquired, thedescription is not limited to this, and the overlay error may beacquired for an m^(th) layer (lower layer, m is an integral number of 1or more) and an n^(th) layer (upper layer, n is an integral number of 2or more and is larger than m). In this case, the n^(th) layer does notnecessarily have to be the following layer of the m^(th) layer.

As is described so far, with substrate processing system 1000 accordingto the embodiment, multiple wafers are processed continuously, by eachof measurement system 500 ₁, measurement system 500 ₂, and a lithographysystem including exposure apparatus 200 and C/D 300. In substrateprocessing system 1000, measurement processing described earlier on themeasurement target wafer described earlier by measurement system 500 ₁,processing by the lithography system (resist coating, exposure, anddeveloping) with respect to the wafer that has undergone measurement bymeasurement system 500 ₁, and measurement processing on the wafer thathas completed processing by the lithography system are performedindependent of each other. Therefore, while there is a restriction thatthe processing by the lithography system is performed on wafers whichhave completed measurement processing by measurement system 500 ₁ andthe measurement processing by measurement system 500 ₂ is performed onwafers which have completed processing by the lithography system, thetotal processing sequence can be decided so that the throughput of theentire substrate processing system 1000 becomes maximum.

Also, with substrate processing system 1000, alignment measurement ofthe target wafer can be performed by measurement device 100 _(i) ofmeasurement system 500 ₁ independently from the processing operation ofthe target wafer by exposure apparatus 200 including the simple EGAmeasurement and exposure described earlier, which allows an efficientprocessing that hardly lowers throughput of wafer processing by exposureapparatus 200. Also, as the entire substrate processing system 1000, byconcurrently performing alignment and exposure processing by exposureapparatus 200 on a wafer in a certain lot on which measurementprocessing has been performed in advance with measurement device 100_(i) of measurement system 500 ₁, measurement processing on a wafer inanother lot with measurement device 100 _(i) of measurement system 500₁, and measurement processing by measurement system 500 ₂ on a waferfurther in another lot on which processing by the lithography system hasbeen completed, it becomes possible to perform an efficient processingthat hardly lowers throughput of wafer processing. Moreover, withmeasurement system 500 ₁, concurrently with wafer alignment and exposureoperation on wafers of a certain lot in exposure apparatus 200,full-shot EGA in which all shots serve as sample shots can be performedon wafers of another lot.

Also, with measurement device 100 _(i) (i=1 to 3) of measurement system500 ₁, full-shot EGA in which all shots serve as sample shots isperformed prior to (to be more precise, prior to resist coating onwafers) operations of wafer alignment and exposure by exposure apparatus200 on wafers of the same lot that has undergone processing process in apre-process of wafer processing (such as; etching, oxidation/diffusion,film deposition, ion implantation, and flattening (CMP)), and for eachwafer that has undergone alignment measurement, alignment history dataincluding wafer grid information (e.g., data on deformation componentsof the wafer grid) is acquired. The alignment history data for eachwafer that has been acquired is stored in the internal storage devicefor each wafer by measurement system controller 530 ₁. Accordingly, withexposure apparatus 200, wafer alignment and exposure can be performed onthe target wafer, effectively using alignment history data for thetarget wafer including wafer grid information obtained using measurementsystem controller 530 ₁. That is, in substrate processing system 1000according to the embodiment, it can be said that alignment history dataincluding wafer grid information (e.g., data on deformation componentsof the wafer grid) on the target wafer obtained in the pre-measurementprocessing in measurement device 100 _(i) (i=1 to 3) of measurementsystem 500 ₁ is substantially transferred (supplied) in a feed-forwardmanner to exposure apparatus 200.

Also, since coefficients of high-order components in the model formulaobtained in the full-shot EGA in the pre-measurement processing inmeasurement device 100 _(i) (i=1 to 3) can be employed in exposureapparatus 200 without any changes, exposure apparatus 200 only has toobtain coefficients of low-order components of the model formuladescribed above by performing alignment measurement in which severalshots serve as alignment shots, and by using this coefficients oflow-order components and coefficients of the high-order componentsacquired in measurement device 100 _(i), not only coefficients(undetermined coefficients) of model formula (1) but also coefficients(undetermined coefficients) of high-order component can also bedetermined, and then by using this model formula (1) whose undeterminedcoefficients are determined (that is, formula (3) described above) anddesign values (X, Y) of the arrangement of the plurality of shots on thewafer, correction amounts from design positions of each shot can beobtained, which allows correction amounts of high accuracy to beacquired similarly to the case when coefficients of low-order componentsand high-order components of model formula (1) are obtained in exposureapparatus 200. Then, based on this correction amounts and the designvalues of the arrangement of the plurality of shots on the wafer, thepositioning target positions of each shot on exposure can be calculated.Accordingly, by controlling the position of wafer stage WST according tothis target position, positioning of each shot can be performed withhigh accuracy with respect to the exposure position (projection positionof the reticle pattern). This allows overlay accuracy of the image ofthe reticle pattern and the pattern formed in each shot area on thewafer to be improved, without any decrease in throughput of exposureapparatus 200.

Also, with measurement device 100 _(i) (i=1 to 6) according to theembodiment, controller 60 _(i) acquires position information on slider10 with respect to surface plate 12 and relative position informationbetween mark detection system MDS and surface plate 12 using the firstposition measurement system 30 and the second position measurementsystem 50, while controlling the movement of slider 10 with drive system20, and also obtains position information on a plurality of marks formedon wafer W using mark detection system MDS. Accordingly, according tomeasurement device 100 _(i), position information on the plurality ofmarks formed on wafer W can be obtained with high accuracy.

Also, with measurement device 100 _(i) (i=1 to 6) according to theembodiment, controller 60 _(i) constantly acquires measurementinformation (relative position information between surface plate 12 andmark detection system MDS) by the second position measurement system 50,and controls the position of surface plate 12 in directions of sixdegrees of freedom via (the actuators of) the three vibration isolators14 real time, so that the positional relation between the detectioncenter of mark detection system MDS and the detection point of the firstposition measurement system which detects position information on slider10 in directions of six degrees of freedom with respect to surface plate12 is maintained to a desired relation at a nm level. Also, controller60 _(i) acquires measurement information (position information on slider10 with respect to surface plate 12) from the first position measurementsystem 30 and measurement information from the second positionmeasurement system 50 (relative position information between surfaceplate 12 and mark detection system MDS) while controlling the movementof slider 10 by drive system 20, and obtains position information on theplurality of wafer marks, based on detection signals at the time whenmarks formed on wafer W are detected using mark detection system MDS,measurement information by the first position measurement system 30obtained at the time when marks formed on wafer W are detected usingmark detection system MDS, and measurement information by the secondposition measurement system 50 obtained at the time when marks formed onwafer W are detected using mark detection system MDS. Accordingly, withmeasurement device 100 _(i), position information on the plurality ofmarks formed on wafer W can be obtained with high accuracy.

Note that, for example, in the case of performing position control ofwafer W (wafer stage WST) on exposure based on the position informationon the marks that are measured, without performing EGA operation usingthe position information on the marks that are measured, for example,measurement information by the second position measurement system 50described above does not have to be used when calculating the positioninformation on the marks. However, in this case, measurement informationby the second position measurement system 50 obtained when detecting themarks formed on wafer W using mark detection system MDS may be offsetand used to correct information used for moving wafer W, such as, forexample, positioning target position of wafer W (wafer stage WST). Or,movement of reticle R (reticle stage RST) at the time of exposure may becontrolled, taking into consideration the offset described above.

Also, with measurement device 100 _(i) (i=1 to 6) according to theembodiment, since the first position measurement system 30 whichmeasures position information in directions of six degrees of freedom ofslider 10 on which wafer W is mounted and held at least detects wafermarks on wafer W with mark detection system MDS, measurement beam cancontinue to irradiate the measurement beam on grating RG1 from headsection 32 in the range that slider 10 moves. Accordingly, the firstposition measurement system 30 can measure the position informationcontinuously; in the entire range within the XY plane that slider 10moves for mark detection. Accordingly, for example, in the manufacturingstage (including the start-up stage of the apparatus in a semiconductormanufacturing plant) of measurement device 100 _(i), by performingorigin setting of the orthogonal coordinate system (reference coordinatesystem) set by the measurement axes of the first position measurementsystem 30, it becomes possible to control an absolute position of slider10, and as a consequence, an absolute position of the marks (not onlysearch marks and wafer marks, but includes other marks, such as, overlaymeasurement marks (registration marks) and the like) formed on wafer Wheld on slider 10 obtained from the position information on slider 10and the detection results of mark detection system MDS on the referencecoordinate system.

As is obvious from the description so far, with substrate processingsystem 1000 according to the embodiment, since the system is equippedwith measurement systems 500 ₁ and 500 ₂, even in the case exposureapparatus 200 only has the function of performing a simple EGA (e.g.,acquiring position information on around 3 to 16 wafer marks usingalignment system AS) to obtain linear components of the correctionamounts of the position coordinates of the wafer within a predeterminedamount of time (the amount of time allowed to maintain required highthroughput), by using the low-order components of deformation of thewafer grid obtained performing the simple EGA measurement and thehigh-order components of deformation of the wafer grid obtained inadvance by measurement system 500 ₁ (or measurement system 500 ₂),obtained, for example, by full-point EGA, deformation of the wafer gridcan be obtained with high precision. Accordingly, by measurement system500 ₁ (or measurement system 500 ₂), grid correction function ofexposure apparatus 200 can be substantially improved. Accordingly, anexposure apparatus that does not have the latest grid correctionfunction can perform exposure with respect to a wafer with highprecision, with high throughput, or without reducing the throughput.

Note that with substrate processing system 1000 according to theembodiment described above, while the case has been described in whichmeasurement device 100 _(i), C/D 300, and exposure apparatus 200 areequipped with a bar code reader, instead of the bar code reader, thesystem may be equipped with a writing/reading device of a RFID tag whichis a wireless IC tag. In such a case, by attaching the RFID tag to eachwafer, measurement device 100 _(i) writing the alignment history datadescribed earlier into the RFID tag for each wafer using thewriting/reading device, and another device such as, for example,exposure apparatus 200 reading the alignment history data from the RFIDtag of a target wafer using the writing/reading device, feedforwardtransfer of the alignment history data for the target wafer describedearlier can be easily realized.

Also, with substrate processing system 1000 according to the embodimentdescribed above, the case has been described in which exposure apparatus200 obtains the coefficients of the low-order components of thefirst-order or less of the model formula described above, and thesecoefficients of the low-order components and the coefficients of thehigh-order components of the second-order or more of the model formuladescribed above acquired by measurement device 100 _(i) are used.However, this usage is not limited, and for example, coefficients ofcomponents of the second-order or less of the model formula describedabove may be obtained from the detection results of the alignment marksin exposure apparatus 200, and these coefficients of the components ofthe second-order or less and coefficients of the high-order componentsof the third-order or more of the model formula described above acquiredby measurement device 100 ₁ may be used. Or, for example, coefficientsof components of the third-order or less of the model formula describedabove may be obtained from the detection results of the alignment marksin exposure apparatus 200, and these coefficients of the component ofthe third order or less and coefficients of the high-order components ofthe fourth-order or more of the model formula described above acquiredby measurement device 100 ₁ may be used. That is, coefficients ofcomponents of the (N−1)^(th) order (N is a whole number of two or more)or less of the model formula described above may be obtained from thedetection results of the alignment marks in exposure apparatus 200, andthese coefficients of the component of the (N−1)^(th) order or less andcoefficients of the high-order components of the N^(th)-order or more ofthe model formula described above acquired by measurement device 100_(i) may be used.

Note that in the embodiment described above, while measurement device100 ₁ (i=1 to 3) is to obtain coordinates a₃, a₄, a₅ . . . and b₃, b₄,b₅ . . . , of the high-order components of the second-order or more andcoordinates a₀, a₁, a₂, b₀, b₁, b₂ of the low-order components of thefirst-order or less of the model formula (1) expressing a relationbetween design position coordinates X and Y of each shot in the wafercoordinate system (coincides with the reference coordinate system) andcorrection amounts (alignment correction components) dx and dy of theposition coordinates of the shots, since the coefficients of thelow-order components can be obtained in exposure apparatus 200,measurement device 100 _(i) does not necessarily have to obtain thecoefficients of the low-order components.

Note that in substrate processing system 1000 according to theembodiment, in the case measurement unit 40 of measurement device 100_(i) is equipped with the multi-point focal point detection systemdescribe earlier, measurement device 100 _(i) may perform a flatnessmeasurement (also called focus mapping) along with the wafer alignmentmeasurement. In this case, by using results of the flatness measurement,focus leveling control of wafer W at the time of exposure becomespossible without exposure apparatus 200 having to perform flatnessmeasurement.

Note that in the embodiment above, the case has been described in whichmeasurement devices 100 ₁, 100 ₂, and 100 ₃ of measurement system 500 ₁having a similar structure and function concurrently perform alignmentmeasurement processing of the same content on, for example, 25 pieces ofwafers included in the same lot which are divided into three groups withthe wafers in each group serving as measurement target wafers ofmeasurement devices 100 ₁, 100 ₂, and 100 ₃. However, measurementdevices 100 ₁, 100 ₂, and 100 ₃ may concurrently perform alignmentmeasurement processing of the same content on wafers in different lots.For example, wafers in a lot to be exposed with the same exposureapparatus (e.g., exposure apparatus 200) next to the lot being measuredby measurement device 100 ₁ may be measured by measurement device 100 ₂,and wafers in a lot to be exposed with the same exposure apparatus(e.g., exposure apparatus 200) next to the lot being measured bymeasurement device 100 ₂ may be measured by measurement device 100 ₃.

Note that in the embodiment above, the case has been described in whichfrom the viewpoint of giving priority to throughput, the threemeasurement devices 100 ₁, 100 ₂, and 100 ₃ of measurement system 500 ₁share the measurement processing for the 25 pieces of wafers in the samelot, and perform parallel processing. However, in the case measurementaccuracy takes priority over throughput, the measurement processingdescribed above is preferably performed by the same measurement device100 _(i) (i=one of 1 to 3) on the 25 pieces of wafers in the same lot.The reason is that there is an individual difference between the waferholders even in the case measurement devices 100 ₁, 100 ₂, and 100 ₃ areequipped with identical wafer holders, and a subtle difference occurs inthe suction state, which may cause measurement errors in measurementdevices 100 ₁, 100 ₂, and 100 ₃. Taking into consideration such points,in the case the 25 pieces of wafers in the same lot are to be measuredsharing the processing among three or two measurement devices 100 _(i)of measurement system 500 ₁, measurement errors caused by the individualdifference among wafer holders may be obtained in advance, for example,by performing flatness measurement on the wafer holders using the samesuper flat wafer, and the like. Note that also in the case the pluralityof wafers in the same lot are not divided among three or two measurementdevices 100 _(i) of measurement system 500 ₁, measurement errors causedby the individual difference among wafer holders may be obtained inadvance, using the super flat wafer. Also, measurement errors caused bythe individual difference among wafer holders of measurement devices 100_(i) (i=4 to 6) may be obtained in advance, using the super flat wafer,regardless of sharing or not sharing the measurement of the plurality ofwafers in the same lot among three or two measurement devices 100 _(i)of measurement system 500 ₁.

Also, the three measurement devices 100 ₄ to 100 ₆ of measurement system500 ₂ may be adjusted using, for example, a reference wafer, so thatsubstantially the same measurement results can be obtained in the caseof performing measurement processing, for example, on one wafer in onelot under the same conditions in each of the three measurement devices100 ₄ to 100 ₆.

Also, whether to give priority to throughput or to measurement accuracyas is described above is preferably made selectable by the user ofmeasurement system 500 ₁. Also, when actually operating measurementsystem 500 ₁, operation efficiency of each measurement device 100 _(i)has to be taken into consideration, and measurement devices 100 ₁, 100₂, and 100 ₃ are not necessarily constantly available (in anon-operating state) at the same time. Accordingly, only in the case twoor more measurement devices 100 _(i) are available at the same time, thewafers in the same lot may be apportioned to the two or more measurementdevices 100 _(i).

Also, for example, at least one of measurement devices 100 ₁, 100 ₂, and100 ₃ of measurement system 500 ₁ may be a measurement device having afunction different from other measurement devices. For example, onemeasurement device may be a measurement device equipped with amulti-point focal point detection system for performing unevenness(flatness) measurement of the wafer surface, or may be a wafer shapemeasurement apparatus. Also, at least one of measurement systems 500 ₁and 500 ₂ may be equipped with two, four, or more than four measurementdevices.

Also, in the embodiment above, the wafers in the same lot serve asmeasurement targets for measurement device 100 ₁ of measurement system500 ₁, as well as measurement targets for measurement device 100 ₂.However, the embodiment is not limited to this, and wafers of a certainlot (e.g., a lot to be sent to exposure apparatus 200) may serve asmeasurement targets for measurement device 100 ₁, and wafers of anotherlot (e.g., a lot to be sent to an exposure apparatus other than exposureapparatus 200) may serve as measurement targets for measurement device100 ₂. In this case, upon setting a measurement condition (a firstpredetermined condition) suitable for measuring the marks on the wafersof the measurement target lot, measurement device 100 ₁ may performmeasurement of the measurement target marks, and upon setting ameasurement condition (a second predetermined condition) suitable formeasuring the marks on the wafers of the measurement target lot,measurement device 100 ₂ may perform measurement of the measurementtarget marks.

Also, in the embodiment above, on overlay error measurement, the wafersin the same lot serve as measurement targets for measurement device 100₄ of measurement system 500 ₂, along with serving as measurement targetsfor measurement device 100 ₅. However, the embodiment above is notlimited to this, and wafers of a certain lot may serve as measurementtargets for measurement device 100 ₄, and wafers of another lot mayserve as measurement targets for measurement device 100 ₅. In this case,upon setting a measurement condition (a first predetermined condition)suitable for measuring the marks on the wafers of the measurement targetlot, measurement device 100 ₄ may perform measurement of the measurementtarget marks, and upon setting a measurement condition (a secondpredetermined condition) suitable for measuring the marks on the wafersof the measurement target lot, measurement device 100 ₅ may performmeasurement of the measurement target marks.

Note that in the case measurement device 500 ₆ of measurement system 500₂ has a structure and function similar to at least one of measurementdevices 500 ₄ and 500 ₃, instead of one of, or both measurement devices500 ₄ and 500 ₅, measurement device 500 ₆ can be used.

Note that in the embodiment above, the case has been described in whichsubstrate processing system 1000 is equipped with measurement system 500₁ equipped with a plurality of, as an example, three measurement devices100 ₁ to 100 ₃, and measurement system 500 ₂ equipped with a pluralityof, as an example, three measurement devices 100 ₄ to 100 ₆, to increasethe throughput of the entire substrate processing system 1000 as much aspossible. However, since measurement system 500 ₁ and measurement system500 ₂ have a similar structure, in the embodiment above, the role to beplayed by measurement system 500 ₁ can be played by measurement system500 ₂ instead, and the role to be played by measurement system 500 ₂ canalso be played by measurement system 500 ₁ instead. Accordingly, if thethroughput of the entire substrate processing system 1000 can be reducedto some extent, substrate processing system 1000 may be equipped onlywith one of measurement systems 500 ₁ and 500 ₂, such as, only withmeasurement system 500 ₁. In this case, when measurement system 500 ₁ isequipped with four or more measurement devices 100, two of the four maybe made to play the roles of measurement devices 100 ₁ and 100 ₂ in theembodiment described earlier, and the remaining two may be made to playthe roles of measurement devices 100 ₄ and 100 ₅.

Note that in the embodiment above, while an example of a case whenperforming overlay error measurement using measurement system 500 ₂ wasdescribed, the embodiment is not limited to this, and measurement system500 ₂, other than overlay error measurement, may simply acquirealignment information (absolute position information, grid informationand the like) of the wafer after exposure and development. Also, inmeasurement system 500 ₂, wafers in the same lot may be apportioned to aplurality of measurement devices 100 _(i) (i=at least two of 4, 5, and6) similarly to the apportioning performed in measurement system 500 ₁.

Also, in substrate processing system 1000 according to the embodimentdescribed above, while measurement systems 500 ₁ and 500 ₂ are notconnected in-line with both exposure apparatus 200 and C/D 300, one of,or both measurement systems 500 ₁ and 500 ₂ may be connected in-linewith exposure apparatus 200 and C/D 300. For example, C/D 300 andmeasurement system 500 ₂ may be connected in-line so that C/D 300 isarranged in between exposure apparatus 200 and measurement system 500 ₂.Or, measurement system 500 ₂ may be connected in-line with both exposureapparatus 200 and C/D 300 so that measurement system 500 ₂ is arrangedin between exposure apparatus 200 and C/D 300. In this case, measurementsystem 500 ₂ does not have to be equipped with carrier system 510.

Also, in the embodiment above, one of measurement systems 500 ₁ and 500₂ does not have to be equipped with a plurality of measurement devices100 _(i). For example, measurement system 500 ₁ may be equipped with aplurality of measurement devices 100 _(i), and measurement system 500 ₂may be equipped with only one measurement device. In this case,measurement processing (at least one of measurement processing of wafergrid and overlay displacement measurement processing) described so farperformed with the plurality of measurement devices on the wafers in thesame lot should be performed, using measurement system 500 ₁. Also, inthis case, a typical overlay measuring instrument may be used instead ofmeasurement system 500 ₂.

Also, in the embodiment above, the case has been described in whichexposure apparatus 200 effectively uses data on deformation componentsof the wafer grid and alignment history data file for each waferacquired with measurement device 100 _(i) (i=1 to 3) of measurementsystem 500 ₁ as pre-measurement data. However, the embodiment is notlimited to this, and based on data on deformation components of thewafer grid and alignment history data file for each wafer acquired withmeasurement device 100 _(i), measurement system controller 530 ₁ (oranalysis device 3000) may obtain process control data and send thisprocess control data in a feedback manner to host computer 2000. As theprocess control data obtained from the data acquired with measurementdevice 100 _(i), control data and the like for film deposition device2300 such as a CVD device, or CMP device 2200 can be representativelygiven. Note that in the embodiment above, measurement device 100 _(i)(i=one of 1 to 3), from data of measurement results obtained by signalprocessor 49 that processes detection signals of mark detection systemMDS equipped in the measurement device, is to select only measurementresults of wafer marks whose waveforms of detection signals obtained asdetection results of mark detection system MDS are favorable, tocontroller 60 _(i). In other words, signal processor 49 also acquiresmeasurement results of wafer marks whose waveforms of detection signalsare not favorable. Accordingly, measurement system controller 530 ₁ (oranalysis device 3000) may obtain data of measurement results for allwafer marks including measurement results of wafer marks whose waveformsof detection signals are not favorable from signal processor 49, andbased on the data, may obtain the process control data. Or, signalprocessor 49 may send data of measurement results for all wafer marks tocontroller 60 _(i), and controller 60 _(i) may perform judgment ofwhether the detection signals obtained as measurement results by markdetection system MDS are favorable or not. In this case, controller 60_(i) may send data of measurement results for all wafer marks includingthe measurement results for wafer marks that were not used for EGAoperation to measurement system controller 530 (or analysis device3000), and based on the data sent, measurement system controller 530 ₁(or analysis device 3000) may obtain the process control data.

Note that in the embodiment above, while the subject is to be a 300 mmwafer, the embodiment is not limited to this, and the wafer may be a 450mm wafer that has a diameter of 450 mm, or a 200 mm wafer that has adiameter of 200 mm. Since wafer alignment can be performed bymeasurement device 100 _(i) separately from exposure apparatus 200, forexample, full-point EGA measurement and the like becomes possible evenon a 450 mm wafer or a 200 mm wafer, without decreasing throughput inexposure processing. Note that in at least one of measurement system 500₁ and measurement system 500 ₂, diameters of the wafers measured may bedifferent in one measurement device and other measurement devices. Forexample, measurement device 100 ₁ of measurement system 500 ₁ maymeasure a 300 mm wafer, and measurement device 100 ₂ may measure a 450mm wafer.

Note that in measurement device 100 _(i) according to the embodimentdescribed above, while the case has been described where the X-axisdirection and the Y-axis direction serve as periodic directions in eachof gratings RG1, RG2 a, and RG2 b, the description is not limited tothis, and in the grating section (two-dimensional grating) that thefirst position measurement system 30 and the second position measurementsystem 50 are each equipped with, the periodic direction only has to betwo directions that intersect each other in the XY plane.

Also, the structure of measurement device 100 _(i) described in theembodiment above is a mere example. For example, the measurement deviceonly has to be structured so that the device has a movable stage (slider10) with respect to base member (surface plate 12) and positioninformation on the plurality of marks on the substrate (wafer) held onthe stage can be measured. Accordingly, the measurement device does notnecessarily have to be equipped with, for example, the first positionmeasurement system 30 and the second position measurement system 50.

Also, it is a matter of course that the structure of head section 32 ofthe first position measurement system 30 described in the embodimentabove and the arrangement of the detection points are mere examples. Forexample, the position of the detection points of mark detection systemMDS and the detection center of head section 32 does not have to matchin at least one of the X-axis direction and the Y-axis direction. Or,the arrangement of the head section of the first position measurementsystem 30 and grating RG1 (grating section) may be opposite. That is,the head section may be provided at the head section, and the gratingsection may be provided at surface plate 12. Also, the first positionmeasurement system 30 does not necessarily have to be equipped withencoder system 33 and laser interferometer system 35, and the firstposition measurement system 35 may be structured only by the encodersystem. The first position measurement system may be structured by anencoder system which measures position information on slider 10 indirections of six degrees of freedom with respect to surface plate 12 byirradiating a beam on grating RG1 of slider 10 from the head section andreceiving the return beam (diffraction beam) from the grating. In thiscase, the structure of the head section does not matter in particular.The first position measurement system 30 does not necessarily have to becapable of measuring position information on slider 10 in directions ofsix degrees of freedom with respect to surface plate 12, and forexample, and may only be capable of measuring position information inthe X, the Y, and the θz directions. Also, the first positionmeasurement system which measures the position information on slider 10with respect to surface plate 12 may be arranged in between surfaceplate 12 and slider 10. Also, the first measurement system may bestructured by other measurement devices such as an interferometer systemthat measures position information on slider 10 in directions of sixdegrees of freedom with respect to surface plate 12, or in directions ofthree degrees of freedom within a horizontal plane.

Similarly, the structure of the second position measurement system 50described in the embodiment above is a mere example. For example, headsections 52A and 52B may be fixed to the surface plate 12 side, andscales 54A and 54B may be provided integrally with mark detection systemMDS. Also, the second position measurement system 50 may be equippedwith only one, or with three or more head sections. In any case, it isdesirable for the second position measurement system 50 to be able tomeasure the positional relation between surface plate 12 and markdetection system MDS in directions of six degrees of freedom. However,the second position measurement system 50 does not necessarily have tobe capable of measuring the positional relation in all directions of thedirections of six degrees of freedom.

Note that in the embodiment above, the case has been described in whichslider 10 is supported by levitation on surface plate 12 by theplurality of air bearings, and drive system 20 that drives slider 10with respect to surface plate 12 in a non-contact manner is structured,including the first driver 20A that drives slider 10 in the X-axisdirection and the second driver 20B that drives slider 10 integrallywith the first driver 20A in the Y-axis direction. However, thedescription is not limited to this, and drive system 20 may employ adrive system having a structure in which slider 10 is moved indirections of six degrees of freedom on surface plate 12. Such a drivesystem may be structured as an example, using a magnetic levitation typeplanar motor. In such a case, air bearing 18 will not be necessary. Notethat measurement device 100 _(i) may be equipped with a drive system formoving surface plate 12 separate from vibration isolators 14.

Also, in the embodiment described above, while measurement system 500 isequipped with the EFEM system as carrier system 510, instead of the EFEMsystem, a carrier storage device may be installed that can store aplurality of (e.g., three) carriers (such as FOUP) along the Y-axisdirection. In this case, measurement system 500 may be equipped with aplurality of loading ports provided adjacent to each of a plurality ofmeasurement devices 100 _(i), and a carrier carrying device whichperforms delivery of a carrier (such as FOUP) in between the carrierstorage device and a mounting section of the plurality of loading ports.

Note that in the embodiment described above, while the case is describedin which C/D 300 is in-line connected to exposure apparatus 200, insteadof C/D 300, a coating apparatus (coater) that coats a sensitive agent(resist) on a substrate (wafer) may be in-line connected to exposureapparatus 200. In this case, the wafer after exposure is to be carriedinto a developing apparatus (developer) that is not in-line connected tothe exposure apparatus. Or, instead of C/D 300, the developing apparatus(developer) that develops the substrate (wafer) that has been exposedmay be in-line connected to exposure apparatus 200. In this case, awafer on which resist is coated in advance at a different place is to becarried into the exposure apparatus.

In the embodiment described above, while the case has been described inwhich the exposure apparatus is a scanning stepper, the description isnot limited to this, and the exposure apparatus may be a static typeexposure apparatus, or may be a reduction projection exposure apparatusof a step-and-stitch method that synthesizes shot areas.

Furthermore, the embodiment described above can also be applied to amulti-stage type exposure apparatus that is equipped with a plurality ofwafer stages as is disclosed in, for example, U.S. Pat. Nos. 6,590,634,5,969,441, 6,208,407, and the like. Also, the exposure apparatus is notlimited to a dry type exposure apparatus previously described thatperforms exposure of wafer W without going through liquid (water), andthe exposure apparatus may be a liquid immersion type exposure apparatusthat exposes a substrate via liquid as is disclosed in, for example,European Patent Application Publication No. 1420298, InternationalPublication WO 2004/055803, International Publication WO 2004/057590,U.S. Patent Application Publication No. 2006/0231206, U.S. PatentApplication Publication No. 2005/0280791, U.S. Pat. No. 6,952,253 andthe like. Also, the exposure apparatus is not limited to an exposureapparatus used for manufacturing semiconductor devices, and for example,may be an exposure apparatus for liquid crystals used for transferring aliquid crystal display device pattern onto a square glass plate.

Semiconductor devices are manufactured through exposing a sensitiveobject using a reticle (mask) on which a pattern is formed with anexposure apparatus that structures a part of the substrate processingsystem according to each embodiment described above, and through alithography step in which the sensitive object that has been exposed isdeveloped. In this case, highly integrated devices can be manufacturedat high yield.

Note that as is shown in FIG. 14, other than the lithography step, themanufacturing process of semiconductor devices may include steps suchas; a step for performing function/performance design of a device, astep for making a reticle (mask) based on this design step, a deviceassembly step (including a dicing process, a bonding process, and apackage process), and an inspection step.

Note that the disclosures of all publications, InternationalPublications, U.S. Patent Application Publications, and U.S. patentsrelated to exposure apparatuses and the like referred to in theembodiment described above are incorporated herein by reference as apartof the present specification.

While the above-described embodiment of the present invention is thepresently preferred embodiment thereof, those skilled in the art oflithography systems will readily recognize that numerous additions,modifications, and substitutions may be made to the above-describedembodiment without departing from the spirit and scope thereof. It isintended that all such modifications, additions, and substitutions fallwithin the scope of the present invention, which is best defined by theclaims appended below.

What is claimed is:
 1. A measurement system used in a manufacturing linefor micro-devices, comprising: a plurality of measurement devices inwhich each device performs measurement processing on a substrate; and acarrying system to perform delivery of a substrate with the plurality ofmeasurement devices, wherein the plurality of measurement devicesincludes a first measurement device that acquires position informationon a plurality of marks formed on a substrate, and a second measurementdevice that acquires position information on a plurality of marks formedon a substrate, and position information on a plurality of marks formedon a substrate can be acquired under a setting of a first predeterminedcondition in the first measurement device, and position information on aplurality of marks formed on another substrate can be acquired under asetting of a second predetermined condition different from the firstpredetermined condition in the second measurement device.
 2. Themeasurement system according to claim 1, wherein with the anothersubstrate, acquirement of the position information is performed underthe setting of the second predetermined condition in the secondmeasurement device, after acquirement of the position information hasbeen completed under the setting of the first predetermined condition inthe first measurement device.
 3. The measurement system according toclaim 1, wherein the first predetermined condition is different from thesecond predetermined condition in at least one of an irradiatingcondition of a detection light irradiated on the mark, a light receivingcondition when receiving light generated from the mark, and a signalprocessing condition to process photo-electrically converted signalsobtained by receiving the light generated from the mark.
 4. Themeasurement system according to claim 3, wherein each of the firstmeasurement device and the second measurement device is equipped with anoptical system that irradiates the mark with the detection light, andthe irradiating condition includes at least one of; wavelength of thedetection light, light amount of the detection light, and one of NA andσ of the optical system.
 5. The measurement system according to claim 3,wherein a plurality of diffracted lights of a different order isgenerated from the mark, and the light receiving condition includesorder of diffracted light used to acquire the position information. 6.The measurement system according to claim 3, wherein a plurality oflights of a different wavelength is generated from the mark, and thelight receiving condition includes wavelength of light used to acquirethe position information.
 7. The measurement system according to claim1, wherein position information on the plurality of marks formed on anm^(th) layer (m is an integral number of 1 or more) of the substrate isacquired under a setting of the first predetermined condition in thefirst measurement device, and position information on the plurality ofmarks formed on an n^(th) layer (n is an integral number of 2 or moreand is larger than m) of the substrate is acquired under a setting ofthe second predetermined condition in the second measurement device. 8.The measurement system according to claim 7, wherein each of positioninformation on the plurality of marks formed on the m^(th) layer andposition information on the plurality of marks formed on the n^(th)layer is output.
 9. The measurement system according to claim 8, whereinthe plurality of marks formed on the m^(th) layer includes a gratingmark whose periodic direction is in one direction within a predeterminedplane, and the plurality of marks formed on the n^(th) layer includes agrating mark whose periodic direction is in a direction intersectingwith the one direction within a predetermined plane.
 10. The measurementsystem according to claim 7, wherein information obtained, based on theposition information on the plurality of marks formed on the m^(th)layer and the position information on the plurality of marks formed onthe n^(th) layer, is output.
 11. The measurement system according toclaim 10, wherein the plurality of marks formed on the m^(th) layerincludes a first mark, and the plurality of marks formed on the n^(th)layer includes a second mark corresponding to the first mark, and theinformation output includes information related to position displacementof the first mark and the second mark.
 12. The measurement systemaccording to claim 10, wherein the information output includesinformation related to overlay displacement between the m^(th) layer andthe n^(th) layer.
 13. The measurement system according to claim 1,wherein position information on the marks formed the another substrateincluded in the same lot as the substrate on which acquiring theposition information under the setting of the first condition isperformed in the first measurement device, is acquired in the secondmeasurement device under the setting of the second condition.
 14. Themeasurement system according to claim 13, further comprising: a carriersystem which has at least one carrier mounting section where a carrierthat can house a plurality of substrates can be installed, and thecarrying system performs delivery of a substrate with the carriersystem.
 15. The measurement system according to claim 14, wherein thesubstrate and the another substrate included in the same lot are carriedinto the carrier mounting section in a state housed in the carrier,prior to acquiring position information on the plurality of marks. 16.The measurement system according to claim 1, wherein acquiring positioninformation on the plurality of marks performed in at least one of thefirst measurement device and the second measurement device is performedon a substrate after going through at least one processing of; resistcoating before exposure, developing after exposure, cleaning,oxidation/diffusion, film deposition, etching, ion implantation, andCMP.
 17. The measurement system according to claim 16, wherein acquiringposition information of the plurality of marks performed in at least oneof the first measurement device and the second measurement device isperformed on a substrate that has completed developing and is beforeetching.
 18. The measurement system according to claim 1, whereinacquiring position information of the plurality of marks performed in atleast one of the first measurement device and the second measurementdevice is performed on a substrate before coating of a sensitive agentfor the next exposure.
 19. The measurement system according to claim 1,wherein the plurality of measurement devices includes at least one thirdmeasurement device which performs a different type of measurement fromthat of the first measurement device and that of the second measurementdevice with respect to the substrate.
 20. The measurement systemaccording to claim 19, wherein the third measurement device is a devicethat can measure flatness information on a surface of the substrate. 21.The measurement system according to claim 1, wherein the firstmeasurement device comprises: a stage that is movable holding thesubstrate; a drive system that moves the stage; a first positionmeasurement system that can acquire position information on the stage;and a mark detection system that detects a mark formed on the substrate,the measurement system further comprising: a controller that controlsmovement of the stage by the drive system and detects each of theplurality of marks formed on the substrate using the mark detectionsystem, and obtains an absolute position coordinate of each of theplurality of marks, based on detection results of each of the pluralityof marks and position information of the stage obtained using the firstposition measurement system at the time of detection of each of theplurality of marks.
 22. The measurement system according to claim 21,wherein the first position measurement system can acquire positioninformation on the stage in at least directions of three degrees offreedom.
 23. The measurement system according to claim 21, wherein thefirst position measurement system has one of a measurement surfacehaving a grating section and a head section which irradiates themeasurement surface with a beam provided in the stage, and along withirradiating the measurement surface with the beam from the head section,receives a return beam from the measurement surface of the beam so thatposition information of the stage can be acquired.
 24. The measurementsystem according to claim 23, further comprising: a base member in whichthe head section is provided; and a second position measurement systemwhich acquires relative position information between the mark detectionsystem and the base member, wherein the controller controls movement ofthe stage by the drive system, based on position information acquiredusing the second position measurement system and position informationacquired using the first position measurement system.
 25. Themeasurement system according to claim 24, wherein the base membersupports the stage movable in directions of six degrees of freedom whichincludes a first direction and a second direction orthogonal to eachother in a predetermined plane and a third direction perpendicular tothe predetermined plane, and the second position detection system canacquire relative position information in the directions of six degreesof freedom between the mark detection system and the base member. 26.The measurement system according to claim 25, wherein the controlleruses the relative position information between the mark detection systemand the base member within the predetermined plane obtained using thesecond position measurement system as a correction amount, whenobtaining the absolute position coordinates of the plurality of marks.27. The measurement system according to claim 21, wherein the controllerperforms statistical calculation using a plurality of the absoluteposition coordinates of the marks obtained, and obtains a correctionamount from design values of an arrangement of the plurality of dividedareas on the substrate.
 28. The measurement system according to claim 1,wherein the plurality of marks includes alignment marks.
 29. Themeasurement system according to claim 1, wherein the plurality of marksincludes marks used for overlay displacement measurement.
 30. Asubstrate processing system, comprising: the measurement systemaccording to claim 1; and an exposure apparatus that has a substratestage on which the substrate that has completed measurement of positioninformation of the plurality of marks by at least one of the firstmeasurement device and the second measurement device of the measurementsystem is mounted, and to the substrate mounted on the substrate stage,performs alignment measurement in which position information of a partof marks selected from a plurality of marks on the substrate is acquiredand exposure in which the substrate is exposed with an energy beam. 31.A substrate processing system, comprising: a first measurement systemand a second measurement system structured from the measurement systemaccording to claim 1; and an exposure apparatus that has a substratestage on which the substrate that has completed measurement of positioninformation on the plurality of marks by at least one of the firstmeasurement device and the second measurement device of the measurementsystem is mounted, and to the substrate mounted on the substrate stage,performs alignment measurement in which position information on a partof marks selected from a plurality of marks on the substrate is acquiredand exposure in which the substrate is exposed with an energy beam,wherein acquiring position information on the plurality of marksperformed in at least one of the first measurement device and the secondmeasurement device that the first measurement system is equipped with isperformed on a substrate that has gone through at least one processingof; cleaning, oxidation/diffusion, film deposition, etching, ionimplantation, and CMP and is before coating of a sensitive agent for thenext exposure, acquiring position information on the plurality of marksperformed in at least one of the first measurement device and the secondmeasurement device that the second measurement system is equipped withis performed on a substrate before etching processing, the substratehaving been exposed by the exposure apparatus and has been developed,and acquiring position information on the plurality of marks fordifferent substrates by each of the first measurement system and thesecond measurement system is performed concurrently with alignmentmeasurement and exposure to different substrates by the exposureapparatus.
 32. A device manufacturing method, comprising: exposing asubstrate using an exposure apparatus that structures a part of thesubstrate processing system according to claim 30, and developing thesubstrate that has been exposed.
 33. A device manufacturing method,comprising: exposing a substrate using an exposure apparatus thatstructures a part of the substrate processing system according to claim31, and developing the substrate that has been exposed.
 34. Ameasurement system used in a manufacturing line for micro-devices,comprising: a first measurement device that performs measurementprocessing on a substrate; and a second measurement device that performsmeasurement processing on a substrate, wherein a substrate that has beenmeasured by one of the first measurement device and the secondmeasurement device can be measured by the other of the first measurementdevice and the second measurement device.
 35. The measurement systemaccording to claim 34, wherein the one of the first measurement deviceacquires position information on a plurality of marks formed on asubstrate, and the other of the second measurement device acquiresposition information on a plurality of marks formed on the substrate.36. A substrate processing system, comprising: the measurement systemaccording to claim 34; and an exposure apparatus that has a substratestage on which the substrate that has completed measurement of positioninformation of the plurality of marks by at least one of the firstmeasurement device and the second measurement device of the measurementsystem is mounted, and to the substrate mounted on the substrate stage,performs alignment measurement in which position information of a partof marks selected from a plurality of marks on the substrate is acquiredand exposure in which the substrate is exposed with an energy beam. 37.A substrate processing system, comprising: a first measurement systemand a second measurement system structured from the measurement systemaccording to claim 34; and an exposure apparatus that has a substratestage on which the substrate that has completed measurement of positioninformation on the plurality of marks by at least one of the firstmeasurement device and the second measurement device of the measurementsystem is mounted, and to the substrate mounted on the substrate stage,performs alignment measurement in which position information on a partof marks selected from a plurality of marks on the substrate is acquiredand exposure in which the substrate is exposed with an energy beam,wherein acquiring position information on the plurality of marksperformed in at least one of the first measurement device and the secondmeasurement device that the first measurement system is equipped with isperformed on a substrate that has gone through at least one processingof; cleaning, oxidation/diffusion, film deposition, etching, ionimplantation, and CMP and is before coating of a sensitive agent for thenext exposure, acquiring position information on the plurality of marksperformed in at least one of the first measurement device and the secondmeasurement device that the second measurement system is equipped withis performed on a substrate before etching processing, the substratehaving been exposed by the exposure apparatus and has been developed,and acquiring position information on the plurality of marks fordifferent substrates by each of the first measurement system and thesecond measurement system is performed concurrently with alignmentmeasurement and exposure to different substrates by the exposureapparatus.
 38. A device manufacturing method, comprising: exposing asubstrate using an exposure apparatus that structures a part of thesubstrate processing system according to claim 36, and developing thesubstrate that has been exposed.
 39. A device manufacturing method,comprising: exposing a substrate using an exposure apparatus thatstructures a part of the substrate processing system according to claim37, and developing the substrate that has been exposed.